Patent Publication Number: US-2022229921-A1

Title: Timing for user data erasure requests

Description:
BACKGROUND 
     The present invention generally relates to processing user data erasure requests, and more specifically, to control the timing of the processing of user data erasure requests. 
     The collection and storage of large amounts of data of users to perform a wide variety of analytical tasks have drastically increased in recent times. Such data sets include, but are not limited to, Electronic Medical Records (EMR), or Electronic Health Records, personal web browsing and shopping data, usage data for a personal electronic device, and the like. Today&#39;s data storage systems store copious amounts of personal data that can be used to derive valuable population insights from aggregated user data. 
     The General Data Protection Regulation (GDPR) is a regulation in the European Union (EU) on data protection and privacy in the EU that addresses the collection and usage of personal data. The GDPR was created to give individuals control over their personal data. Many other governments have enacted data protection regulations similar to the GDPR. One common provision of these data protection regulations is the right of a user to request that their personal data be removed from stored data sets. 
     SUMMARY 
     Embodiments of the present invention are directed to a computer-implemented method for processing user data erasure requests. A non-limiting example of the computer-implemented method includes receiving a data erasure request associated with a user and identifying, based at least in part on the data erasure request, an entity associated with the user and one or more identifiers for the user. The method also includes identifying, based at least in part on the one or more identifiers for the user, a cohort that includes the user and comparing the one or more identifiers for the user to identifiers of a plurality of users that are not members of the cohort. The method further includes identifying a replacement user from the plurality of users based on the comparison and replacing the entity associated with the user in the cohort with an entity associated with the replacement user. 
     Embodiments of the present invention are directed to a system processing user data erasure requests. A non-limiting example of the system includes a processor communicative coupled to a memory, the processor operable to receive a data erasure request associated with a user and identify, based at least in part on the data erasure request, an entity associated with the user and one or more identifiers for the user. The processor also operable to identify, based at least in part on the one or more identifiers for the user, a cohort that includes the user and compare the one or more identifiers for the user to identifiers of a plurality of users that are not members of the cohort. The processor further operable to identify a replacement user from the plurality of users based on the comparison and replace the entity associated with the user in the cohort with an entity associated with the replacement user. 
     Embodiments of the invention are directed to a computer program product for processing user data erasure requests, the computer program product comprising a computer readable storage medium having program instructions embodied therewith. The program instructions are executable by a processor to cause the processor to perform a method. A non-limiting example of the method includes receiving a data erasure request associated with a user and identifying, based at least in part on the data erasure request, an entity associated with the user and one or more identifiers for the user. The method also includes identifying, based at least in part on the one or more identifiers for the user, a cohort that includes the user and comparing the one or more identifiers for the user to identifiers of a plurality of users that are not members of the cohort. The method further includes identifying a replacement user from the plurality of users based on the comparison and replacing the entity associated with the user in the cohort with an entity associated with the replacement user. 
     Additional technical features and benefits are realized through the techniques of the present invention. Embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed subject matter. For a better understanding, refer to the detailed description and to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The specifics of the exclusive rights described herein are particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the embodiments of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  depicts a cloud computing environment according to one or more embodiments of the present invention; 
         FIG. 2  depicts abstraction model layers according to one or more embodiments of the present invention; 
         FIG. 3  depicts a block diagram of a computer system for use in implementing one or more embodiments of the present invention; 
         FIG. 4  depicts a system for processing user data erasure requests according to embodiments of the invention; 
         FIG. 5  depicts a flow diagram of a method for processing user data erasure requests according to one or more embodiments of the invention; and 
         FIG. 6  depicts a flow diagram of another method for processing user data erasure requests according to one or more embodiments of the invention. 
     
    
    
     The diagrams depicted herein are illustrative. There can be many variations to the diagram or the operations described therein without departing from the spirit of the invention. For instance, the actions can be performed in a differing order or actions can be added, deleted or modified. Also, the term “coupled” and variations thereof describes having a communications path between two elements and does not imply a direct connection between the elements with no intervening elements/connections between them. All of these variations are considered a part of the specification. 
     DETAILED DESCRIPTION 
     Various embodiments of the invention are described herein with reference to the related drawings. Alternative embodiments of the invention can be devised without departing from the scope of this invention. Various connections and positional relationships (e.g., over, below, adjacent, etc.) are set forth between elements in the following description and in the drawings. These connections and/or positional relationships, unless specified otherwise, can be direct or indirect, and the present invention is not intended to be limiting in this respect. Accordingly, a coupling of entities can refer to either a direct or an indirect coupling, and a positional relationship between entities can be a direct or indirect positional relationship. Moreover, the various tasks and process steps described herein can be incorporated into a more comprehensive procedure or process having additional steps or functionality not described in detail herein. 
     The following definitions and abbreviations are to be used for the interpretation of the claims and the specification. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains” or “containing,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, a mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus. 
     Additionally, the term “exemplary” is used herein to mean “serving as an example, instance or illustration.” Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms “at least one” and “one or more” may be understood to include any integer number greater than or equal to one, i.e. one, two, three, four, etc. The terms “a plurality” may be understood to include any integer number greater than or equal to two, i.e. two, three, four, five, etc. The term “connection” may include both an indirect “connection” and a direct “connection.” 
     The terms “about,” “substantially,” “approximately,” and variations thereof, are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” can include a range of ±8% or 5%, or 2% of a given value. 
     For the sake of brevity, conventional techniques related to making and using aspects of the invention may or may not be described in detail herein. In particular, various aspects of computing systems and specific computer programs to implement the various technical features described herein are well known. Accordingly, in the interest of brevity, many conventional implementation details are only mentioned briefly herein or are omitted entirely without providing the well-known system and/or process details. 
     It is to be understood that although this disclosure includes a detailed description on cloud computing, implementation of the teachings recited herein are not limited to a cloud computing environment. Rather, embodiments of the present invention are capable of being implemented in conjunction with any other type of computing environment now known or later developed. 
     Cloud computing is a model of service delivery for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, network bandwidth, servers, processing, memory, storage, applications, virtual machines, and services) that can be rapidly provisioned and released with minimal management effort or interaction with a provider of the service. This cloud model may include at least five characteristics, at least three service models, and at least four deployment models. 
     Characteristics are as follows: 
     On-demand self-service: a cloud consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with the service&#39;s provider. 
     Broad network access: capabilities are available over a network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs). 
     Resource pooling: the provider&#39;s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to demand. There is a sense of location independence in that the consumer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter). 
     Rapid elasticity: capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time. 
     Measured service: cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service. 
     Infrastructure as a Service (IaaS): the capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls). 
     Deployment Models are as follows: 
     Private cloud: the cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on-premises or off-premises. 
     Community cloud: the cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on-premises or off-premises. 
     Public cloud: the cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services. 
     Hybrid cloud: the cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load-balancing between clouds). 
     A cloud computing environment is service oriented with a focus on statelessness, low coupling, modularity, and semantic interoperability. At the heart of cloud computing is an infrastructure that includes a network of interconnected nodes. 
     Referring now to  FIG. 1 , illustrative cloud computing environment  50  is depicted. As shown, cloud computing environment  50  comprises one or more cloud computing nodes  10  with which local computing devices used by cloud consumers, such as, for example, personal digital assistant (PDA) or cellular telephone  54 A, desktop computer  54 B, laptop computer  54 C, and/or automobile computer system  54 N may communicate. Nodes  10  may communicate with one another. They may be grouped (not shown) physically or virtually, in one or more networks, such as Private, Community, Public, or Hybrid clouds as described hereinabove, or a combination thereof. This allows cloud computing environment  50  to offer infrastructure, platforms and/or software as services for which a cloud consumer does not need to maintain resources on a local computing device. It is understood that the types of computing devices  54 A-N shown in  FIG. 1  are intended to be illustrative only and that computing nodes  10  and cloud computing environment  50  can communicate with any type of computerized device over any type of network and/or network addressable connection (e.g., using a web browser). 
     Referring now to  FIG. 2 , a set of functional abstraction layers provided by cloud computing environment  50  ( FIG. 1 ) is shown. It should be understood in advance that the components, layers, and functions shown in  FIG. 2  are intended to be illustrative only and embodiments of the invention are not limited thereto. As depicted, the following layers and corresponding functions are provided: 
     Hardware and software layer  60  includes hardware and software components. Examples of hardware components include: mainframes  61 ; RISC (Reduced Instruction Set Computer) architecture based servers  62 ; servers  63 ; blade servers  64 ; storage devices  65 ; and networks and networking components  66 . In some embodiments, software components include network application server software  67  and database software  68 . 
     Virtualization layer  70  provides an abstraction layer from which the following examples of virtual entities may be provided: virtual servers  71 ; virtual storage  72 ; virtual networks  73 , including virtual private networks; virtual applications and operating systems  74 ; and virtual clients  75 . 
     In one example, management layer  80  may provide the functions described below. Resource provisioning  81  provides dynamic procurement of computing resources and other resources that are utilized to perform tasks within the cloud computing environment. Metering and Pricing  82  provide cost tracking as resources are utilized within the cloud computing environment, and billing or invoicing for consumption of these resources. In one example, these resources may comprise application software licenses. Security provides identity verification for cloud consumers and tasks, as well as protection for data and other resources. User portal  83  provides access to the cloud computing environment for consumers and system administrators. Service level management  84  provides cloud computing resource allocation and management such that required service levels are met. Service Level Agreement (SLA) planning and fulfillment  85  provides pre-arrangement for, and procurement of, cloud computing resources for which a future requirement is anticipated in accordance with an SLA. 
     Workloads layer  90  provides examples of functionality for which the cloud computing environment may be utilized. Examples of workloads and functions which may be provided from this layer include: mapping and navigation  91 ; software development and lifecycle management  92 ; virtual classroom education delivery  93 ; data analytics processing  94 ; transaction processing  95 ; and processing user data erasure requests  96 . 
     Referring to  FIG. 3 , there is shown an embodiment of a processing system  300  for implementing the teachings herein. In this embodiment, the system  300  has one or more central processing units (processors)  21   a,    21   b,    21   c,  etc. (collectively or generically referred to as processor(s)  21 ). In one or more embodiments, each processor  21  may include a reduced instruction set computer (RISC) microprocessor. Processors  21  are coupled to system memory  34  and various other components via a system bus  33 . Read only memory (ROM)  22  is coupled to the system bus  33  and may include a basic input/output system (BIOS), which controls certain basic functions of system  300 . 
       FIG. 3  further depicts an input/output (I/O) adapter  27  and a network adapter  26  coupled to the system bus  33 . I/O adapter  27  may be a small computer system interface (SCSI) adapter that communicates with a hard disk  23  and/or tape storage drive  25  or any other similar component. I/O adapter  27 , hard disk  23 , and tape storage device  25  are collectively referred to herein as mass storage  24 . Operating system  40  for execution on the processing system  300  may be stored in mass storage  24 . A network adapter  26  interconnects bus  33  with an outside network  36  enabling data processing system  300  to communicate with other such systems. A screen (e.g., a display monitor)  35  is connected to system bus  33  by display adaptor  32 , which may include a graphics adapter to improve the performance of graphics intensive applications and a video controller. In one embodiment, adapters  27 ,  26 , and  32  may be connected to one or more I/O busses that are connected to system bus  33  via an intermediate bus bridge (not shown). Suitable I/O buses for connecting peripheral devices such as hard disk controllers, network adapters, and graphics adapters typically include common protocols, such as the Peripheral Component Interconnect (PCI). Additional input/output devices are shown as connected to system bus  33  via user interface adapter  28  and display adapter  32 . A keyboard  29 , mouse  30 , and speaker  31  all interconnected to bus  33  via user interface adapter  28 , which may include, for example, a Super I/O chip integrating multiple device adapters into a single integrated circuit. 
     In exemplary embodiments, the processing system  300  includes a graphics processing unit  41 . Graphics processing unit  41  is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display. In general, graphics processing unit  41  is very efficient at manipulating computer graphics and image processing and has a highly parallel structure that makes it more effective than general-purpose CPUs for algorithms where processing of large blocks of data is done in parallel. 
     Thus, as configured in  FIG. 3 , the system  300  includes processing capability in the form of processors  21 , storage capability including system memory  34  and mass storage  24 , input means such as keyboard  29  and mouse  30 , and output capability including speaker  31  and display  35 . In one embodiment, a portion of system memory  34  and mass storage  24  collectively store an operating system to coordinate the functions of the various components shown in  FIG. 3 . 
     Turning now to an overview of technologies that are more specifically relevant to aspects of the invention, in big data applications, such as a multi-tenant healthcare system, user data is stored in data reservoirs and/or data warehouses for consumption by various applications, such as business intelligence tools. Data reservoirs enable all forms of the customer (e.g., healthcare providers) specific data to be stored in a uniform, single large storage repository for access by a data processing engine. Data reservoirs may be used for multi-dimensional analytics to discover optimal business outcomes. Data reservoirs may be single-tenant, where the data is stored and owned by a single entity, or multi-tenant, where data is stored and owned by multiple entities. Multi-tenant data reservoirs isolate specific tenant data from all other tenants. Multi-tenant data reservoirs may maximize the storage use of a database and provide uniform security and decryption of data. Similarly, a data warehouse is a central repository of integrated data from one or more disparate data sources. They store current and historical data in one single place that are used for creating analytical reports. 
     In exemplary embodiments, the data reservoirs and/or data warehouses are configured to store data associated with a large number of users. Each user is represented by an entity, or set of records, that includes one or more identifiers of the user, such as demographics of the user. The one or more identifiers can include a user&#39;s name, age, address, and other information such as medical conditions, education level, income level, and the like of the user. 
     In exemplary embodiments, the data processing engines and business intelligence tools are configured to create cohorts, or groups of users, based on the identifiers of the users stored in the data reservoirs and/or data warehouses to derive population insights from aggregated user data. In exemplary embodiments, once cohorts are created, processor-intensive analytics are performed on the cohort to derive the population insights. In exemplary embodiments, a cohort includes a sampling of users that have identifiers that fit into an identified group, such as an age range or a geographic area. In general, the cohort does not include all users that have identifiers that fit into the identified group. In exemplary embodiments, a cohort must have a minimum percentage of the total population size. For example, if the data set includes one thousand users, the cohort must include at least ten percent or one hundred uses. In these cases, a change in the cohort size can shift the statistical significance of analytics performed on the cohort. 
     Turning now to an overview of the aspects of the invention, one or more embodiments of the invention provide for processing user data erasure requests. In exemplary embodiments, the timing of the processing of data erasure requests is controlled to minimize the impact that the data erasure requests on the population insights from the aggregated user data. In one embodiment, data erasure requests are queued by a data processing engine, which is configured to determine identifiers of the user associated with the erasure request and to identify cohorts the identifiers are members of. The data processing engine is also configured to identifying a suitable replacement user for the cohort and to, if necessary, delay the processing of the data erasure request until a suitable replacement user for the cohort is found. Once a suitable replacement user for the cohort is identified, the data processing engine replaces the user in the cohort and reprocessing downstream usage of the data. In exemplary embodiments, when a user of a cohort is replaced, the data processing engine  402  is configured to notify cohort subscribers, entities that utilize the cohort data, that a replacement has been made. 
     Turning now to a more detailed description of aspects of the present invention,  FIG. 4  depicts a system for processing user data erasure requests according to embodiments of the invention. The system  400  includes a data processing engine  402 , a user device  404 , and a data warehouse  406 . In one or more embodiments of the invention, the data processing engine  402  and the data warehouse  406  can be implemented on the processing system  300  found in  FIG. 3 . Additionally, the cloud computing system  50  can be in wired or wireless electronic communication with one or all of the elements of the system  400 . Cloud  50  can supplement, support or replace some or all of the functionality of the elements of the system  400 . Additionally, some or all of the functionality of the elements of system  400  can be implemented as a node  10  (shown in  FIGS. 1 and 2 ) of cloud  50 . Cloud computing node  10  is only one example of a suitable cloud computing node and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention described herein. The user device  404  can be any type of device that a user may utilize to create and transmit a data erasure request including a smartwatch, smartphone, laptop, and the like. 
     In exemplary embodiments of the invention, once a data erasure request is received from a user device  404 , the data processing engine  402  queues an erasure request and obtains an entity associated with the user. Based on the entity associated with the user, the data processing engine  402  determines one or more identifiers for the user and a cohort that the user is a part of. The data processing engine  402  obtains identifiers for a plurality of users that are not currently part of the cohort and identifies a suitable replacement for the user in the cohort from the plurality of users that are not currently part of the cohort. In exemplary embodiments, the data erasure request remains in the queue until a suitable replacement for the cohort or until a predefined time period has passed. If at the end of the predefined time period, a suitable replacement has not been identified, the best replacement from the available replacements may be placed in the cohort. In exemplary embodiments, delaying the removal process, up to a predefined time period, balances due diligence in quickly complying with the data erasure request with maintaining progress in the cohort. 
     In exemplary embodiments, the data processing engine  402  identifies a suitable replacement by processing data of users that are not currently part of the cohort to determine whether the user is a match for the cohort. In exemplary embodiments, the pool of users that are considered for replacement of the user in a cohort includes users that have been added to the data set since the cohort was first generated. In exemplary embodiments, the suitable replacement is identified by comparing the identifiers of the user that is being removed and the identifiers of the users being considered. The comparison includes performing a statistical analysis on the identifiers to determine a user that is not part of the cohort that has the highest similarity to the user being removed. Once the replacement user is identified, the user is replaced in the cohort, which triggers downstream reprocessing of the data represented by the cohort. After the user has been replaced in the cohort, the erasure request is completed, and the data of the user is removed from the data warehouse  406 . 
     In some embodiments, a single user may be a part of multiple cohorts and a data erasure request can trigger the replacement of the user in each cohort. In one embodiment, the user is a member of two cohorts and is replaced by different users in each of the two cohorts. This may happen for multiple reasons. For example, the location of the user may have changed during the time period that the data covers, i.e., the user moved from New York to Florida. In another example, the data of the user spans two different age cohorts, i.e., the data of the user covers the time from when the user is 50-65 and the cohorts are ages 50-60 and 61-65. 
       FIG. 5  depicts a flow diagram of a method for processing user data erasure requests according to one or more embodiments of the invention. The method  500  includes receiving a data erasure request associated with a user, as shown at block  502 . Next, as shown at block  504 , the method  500  includes identifying, based at least in part on the data erasure request, an entity associated with the user and one or more identifiers for the user. In exemplary embodiments, the entity is a set of records that contain data regarding the user. Next, as shown at block  506 , the method includes identifying, based at least in part on the one or more identifiers for the user, a cohort that includes the user. In one example, the identifiers for the user include demographic information regarding the user, such as age, geographic location, gender and the like. In one embodiment, a cohort is a sampling of users that have an identifier that falls within a predetermined group, such as males, age 20-30, with a location of the northeastern United States. 
     The method  500  also includes comparing the one or more identifiers for the user to identifiers of a plurality of users that are not members of the cohort, as shown at block  508 . In exemplary embodiments, comparing the one or more identifiers for the user to identifiers of the plurality of users that are not members of the cohort includes calculating a similarity score between the user and each of the plurality of users that are not members of the cohort. 
     In one embodiment, the similarity score is a weighted average comparison between the identifiers of the user to be removed and the identifiers of the user that is not a member of the cohort. For example, the similarity score (S) may be defined as: 
         S=A* (Gender Match)+ B* (Location Match)+ C* (Age Match) 
     where A, B, and C are weighting factors that can be set by a user. Gender Match is a 1 if the gender of the user under consideration matches the user to be replaced and 0 otherwise. Location Match is a number between 1 and 0 that is 1 if the location of the user under consideration is the same as the user to be replaced and decreases as the distance between the locations of the users increase. Age Match is a number between 1 and 0 that is 1 if the age of the user under consideration is the same as the age of the user to be replaced decreases as the difference in age between the users increases. As will be appreciated by those of ordinary skill in the art, other identifiers can also be used in calculating the similarity score 
     Next, as shown at block  510 , the method  500  includes identifying a replacement user from the plurality of users based on the comparison. In one embodiment, the replacement user is identified as having the highest similarity score of the calculated similarity scores. The method  500  concludes by replacing the entity associated with the user in the cohort with an entity associated with the replacement user. In exemplary embodiments, replacing the entity associated with the user in the cohort includes completing the data erasure request by deleting the entity associated with the user. 
       FIG. 6  depicts a flow diagram of another method for processing user data erasure requests according to one or more embodiments of the invention. The method  600  includes receiving a data erasure request associated with a user, obtain identifiers for the user, and identify a cohort the user belongs to, as shown at block  602 . Next, as shown at block  604 , the method  600  includes obtaining identifiers for a plurality of users that are not members of the cohort. The method  600  also includes calculating a similarity score between the user and the plurality of users that are not members of the cohort, as shown at block  606 . The method  600  then proceeds to decision block  608  and determines if the highest similarity score is greater than a threshold value. If the highest similarity score is greater than a threshold value, the method  600  proceeds to block  610  and replaces an entity associated with the user in the cohort with an entity associated with the user having the highest similarity score. If the highest similarity score is not greater than a threshold value, the method  600  proceeds to block  612  and waits a time period. After the time period, the method  600  proceeds to block  614  and obtains identifiers for a plurality of users that are not members of the cohort, including new users added during the time period. Next, as shown at block  616 , the method  600  includes calculating a similarity score between the user and the plurality of users that are not members of the cohort. The method concludes at block  610  by replacing an entity associated with the user in the cohort with an entity associated with the user having the highest similarity score. In exemplary embodiments, replacing the entity associated with the user in the cohort includes completing the data erasure request by deleting the entity associated with the user. In exemplary embodiments, a duration of the time period is determined based on a statutory requirement for complying with a data erasure request. 
     Additional processes may also be included. It should be understood that the processes depicted in  FIGS. 5 and 6  represent illustrations, and that other processes may be added or existing processes may be removed, modified, or rearranged without departing from the scope and spirit of the present disclosure. 
     The present invention may be a system, a method, and/or a computer program product at any possible technical detail level of integration. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention. 
     The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device. 
     Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++, or the like, and procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instruction by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention. 
     Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. 
     These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments described herein.