Abstract:
A calendar of a calendar owner can be identified. The calendar can include at least one calendar entry. Each calendar entry can be associated with access restrictions specific to the entry and/or a type associated with the entry. An attempt from a non-owner to access the calendar of the owner can be received. A relationship between the non-owner and the owner can be determined, which is used to grant access privileges. A non-owner can be permitted to access/change the owner&#39;s calendar entries based upon comparisons of the granted privileges and the access restrictions. For example, when certain approved people view busy-time scheduled in a user&#39;s calendar, any non-important booked time can be shown as time availably for scheduling events with the user. When an approved person schedules a previously book time slot, and an owner agrees to this change, then existing appointments are automatically rescheduled/adjusted to avoid conflicts.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to the field of scheduling, more particularly to enhanced viewing/updating of calendar entries based upon relationships between a viewer and a calendar owner and a relative importance value of the calendar entries. 
         [0002]    Many computing applications provide users with a shared calendar. Some applications implement shared calendars where users get their own calendars and others can implement a common calendar for multiple users to share. Often, both private and group calendars can be provided in collaborative software. Collaborative software is also used in social networking settings and other settings where a distributed set of people need to coordinate with each other. 
         [0003]    When personal calendars for users are provided, they can typically be shared with other users. When other users view shared calendars, they can see which time is scheduled and what time the user has free. In one example, a shared calendar can be used in a professional environment. Each employee&#39;s calendar can reflect their schedule for their daily activities at work. The employee&#39;s calendar can also reflect instances where personal time has been scheduled. Regardless of who views the calendar, the viewer will see all the scheduled time in a unified manner. A user, however, may desire their boss in a business context or their spouse in a personal context to have enhanced viewing and/or calendar manipulation options available for calendaring events. For example, a boss would have access to change/view business related meeting events of an owner&#39;s. In another example, a spouse would have similar leeway for family related scheduled events within an owner&#39;s calendar. Conventional calendaring systems do not customize calendar actions based upon a relationship between an owner and an accessing party. Additionally, existent calendaring systems make no distinctions between different types of calendar entries 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    One aspect of the present invention can include a collaborative calendaring system that includes a data store, a categorization engine, an event scheduling engine, a relationship engine, and/or other functional components. The data store can digitally encode calendar data specifying a set of calendar entries associated with different calendar owners. The calendaring engine can distinguish between calendar entries representing genuine meetings and user created time blocks set aside to permit an owner of the calendar to complete a task. The event scheduling engine can permit non-owners to push new calendar entries into an owner&#39;s calendar even when the new calendar entries conflict with at least one of previously established entries for a time block set aside to permit the owner of the calendar to complete a task. The pushing of a new calendar entry to a calendar of an owner does not necessarily require explicit owner permission to be granted at a time that the pushing of the new calendar entry occurs. 
         [0005]    Another aspect of the present invention can include a method, computer program product, an apparatus, and a system for selectively sharing calendars in a collaborative computing space. In this aspect, a calendar of a calendar owner can be identified. The calendar can include at least one calendar entry. Each calendar entry can be associated with access restrictions specific to the entry and/or a type associated with the entry. For example, entries in a calendar representing user-set aside time to complete a task can have different (e.g., lesser) access restrictions than a calendar entry associated with meeting having multiple attendees. An attempt from a non-owner to access the calendar of the owner can be received. A relationship between the non-owner and the owner can be determined. Access privileges for the non-owner can be determined based at least in part upon the determined relationship. The access privileges can be compared to the access restrictions of each calendar entry. The non-owner can be permitted to access to the calendar entries based upon results of the comparing operation. For example, the comparing operation can permit a non-owner to push new calendar entries into an existing time slot partially occupied by a “task completing” entry, where other calendar entries (such as those associated with a meeting) can be viewed but not modified. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0006]      FIG. 1  is an example scenario for selectively granting different access permissions to an owner&#39;s calendar based upon an accessing user&#39;s relationship with the owner and based upon details of specific calendar entries in accordance with an embodiment of the inventive arrangements disclosed herein. 
           [0007]      FIG. 2  is a schematic diagram of a system for selectively sharing calendar entries in a collaborative computing space, where the sharing varies based upon a relationship between a calendar owner and a user. 
           [0008]      FIG. 3  is a flow chart of a method for selectively sharing calendars in a collaborative computing space in accordance with an embodiment of the inventive arrangements disclosed herein. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0009]    The present invention can allow for the categorization of calendar entries. The calendar entries can have different important levels associated with them, for example, entries relating to meetings with others can have a higher import level (or priority level) than to-do time slot blocked by a calendar owner to accomplish a task (e.g., a to-do item). A “relationship strength” can be determined between an accessing user of another user&#39;s calendar. A user&#39;s relationship and/or relationship strength can be determined in multiple ways. For example, a strength can be based upon a relative placement of the user verses a calendar owner in an organizational hierarchy. In another example, relationship strength can be determined based upon a connectively strength within a social network. A comparison between the relationship strength and the import level of a calendar entry can determine whether the user can view/change the calendar entry. 
         [0010]    The present invention may be embodied as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product on a computer-usable storage medium having computer-usable program code embodied in the medium. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc. 
         [0011]    Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-usable medium may include a propagated data signal with the computer-usable program code embodied therewith, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted using any appropriate medium, including but not limited to the Internet, wireline, optical fiber cable, RF, etc. 
         [0012]    Any suitable computer usable or computer readable medium may be utilized. The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory, a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD. Other computer-readable medium can include a transmission media, such as those supporting the Internet, an intranet, a personal area network (PAN), or a magnetic storage device. Transmission media can include an electrical connection having one or more wires, an optical fiber, an optical storage device, and a defined segment of the electromagnet spectrum through which digitally encoded content is wirelessly conveyed using a carrier wave. 
         [0013]    Note that the computer-usable or computer-readable medium can even include paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. 
         [0014]    Computer program code for carrying out operations of the present invention may be written in an object oriented programming language such as Java, Smalltalk, C++ or the like. However, the computer program code for carrying out operations of the present invention may also be written in conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code 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 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). 
         [0015]    A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. 
         [0016]    Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers. 
         [0017]    Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters. 
         [0018]    The present invention is described below 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 program instructions. These computer 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. 
         [0019]    These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
         [0020]    The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
         [0021]      FIG. 1  is an example scenario  100  for selectively granting different access permissions to an owner&#39;s calendar based upon an accessing user&#39;s relationship with the owner and based upon details of specific calendar entries in accordance with an embodiment of the inventive arrangements disclosed herein. Scenario  100  can include users  124  (Tom),  126  (Jane), and  132  (Harry). The users  124 ,  126 , and  132  can each interact with client devices  120 ,  128 , and  134  having user interfaces  140 ,  150 , and  160 . Each of the devices  120 ,  128 , and  134  can be connected to calendar server  102  through network  150 . System  100  shows a situation where an owner&#39;s  124  (Tom&#39;s) calendar entries are able to be selectively viewed/changed by one or more other users  126 ,  132  based upon a relationship among users  124 ,  126 ,  132  and based upon an importance value associated with calendar entries  154 ,  156 . 
         [0022]    As shown, Tom  124  can interact with calendar server  102  to configure specifics of his calendar. For example, interface  140  can permit an owner (Tom)  124  to establish entry/relationship settings. A selectable tab for relationships  170  can, for example, permit an owner to dictate how relationships and/or relationship strength values are to be determined for purposes of granting access to the owner&#39;s calendar entries. Another selectable tab for entries  172  can establish customizations for determining restrictions that are to be imposed upon calendar entries, such as restrictions based upon calendar entry type (meeting, to-do item, etc), category (work related entry, family related entry, etc.), and other definable criteria. An entry specific tab  174 , which is shown as highlighted, can permit the owner to establish entry specific settings regarding access to be granted to others for a specific calendar entry. When more generic settings exist, the specific settings established via tab  174  can override. In another implementation, a most restrictive or most permissive set of access rules can be applied when conflicts among specific and generalized settings are resolved. 
         [0023]    Entry specific settings  172  can include a selectable control for establishing relationships with other users  142  and for granting variable permissions to these users based upon a type of calendar entry (types shown in interface  140  includes personal, work, family, and health—although any type can be utilized). The interface  140  is also configured using option  143 , to notify the calendar owner (Tom  124 ), when calendar changes are made. Other options can be included, such as an option  144  to prompt a calendar owner before allowing others to modify a calendar entry. Based on the settings established in interface  140 , the calendar server  102  can establish proper permissions for other users  126 ,  132  accessing Tom—s  134  calendar. 
         [0024]    Tom&#39;s  124  calendar  152 ,  162  can be viewed by Jane  126  and Harry  132  using interfaces  150  and  160 . Jane  126  can be related to Tom  124  by birth or marriage. Family based relationships can be granted view only access to entries on Tom&#39;s calendar related to work and view only access to family related entries. In one embodiment, work related entries can be abstracted (or redacted) as shown in entry  156  to hide details, which may be confidential. Details of the personal or family related entries  154  can be presented in full for viewing, in accordance with permissions configured by the calendar owner  124  (using interface  140 ). 
         [0025]    Harry  132  can have a work-related supervisory relationship with Tom  124  (e.g., Harry  132  can be Tom&#39;s boss, supervisor, project leader, etc.). This relationship can grant Harry  132  view permissions over portions of Tom&#39;s  124  calendar (such as personal entries for Tom  124  can be viewed by Harry  132  as shown in interface  140 ) and modify privileges against other portions (e.g., work related entries). In one embodiment, details of entries not related to work can be obscured, as shown by entry  157 , which is marked as personal time. Full details can be provided for a work related entry, as shown by calendar entry  158 . Selection of a modify  166  option permits Harry  132  to manipulate details of the work related entry  158 . For example, Harry  132  can add a different work related meeting for the time of 11:00AM-12:00PM and can reschedule the original meeting having that time slot (entry  158 ) for a different time. 
         [0026]    It should be appreciated that explicit relationship and permissions as shown in system  100  is one contemplated embodiment of the invention. In another embodiment, a calendar owner  124  will not explicitly establish per person privileges, but can establish various privileges for calendar entries based upon a relationship type and strength. The relationship type and strength can be determined based upon relatively static information (e.g., being based upon positions in an organization hierarchy) as well as being based upon dynamic information (e.g., a frequency of communication between two users within a social network). Additionally, a set of owner configurable rules can be used to categorize different types of events and to apply an importance level to events based upon these categories. For example, to-do items appearing in a calendar can be given a lower importance level than meeting events. 
         [0027]      FIG. 2  is a schematic diagram of a system  200  for selectively sharing calendar entries in a collaborative computing space, where the sharing varies based upon a relationship between a calendar owner and a user. In system  200 , a calendar server  202  can manage calendar entries for a plurality of users  224 . Each calendar entry can be associated with an owner, who is the user  224  for whom the calendar entry applies. Other users  224  can view/modify the owner&#39;s calendar entries depending upon their relationship with the owner and depending upon specifics of the calendar entries themselves. 
         [0028]    An event scheduler  204  component of the calendar server  202  can permit managed events to be added, removed, and modified within an associated calendar. For example, the scheduler  204  can permit a non-owner to push new entries to an owners calendar (assuming suitable access rights are granted to the non-owner) even when the new entry conflicts with a pre-existing entry. The scheduler  204  can automatically reschedule, change times of, calendar entries to resolve conflicts caused by the new entry. In one embodiment, non-owners can push times for meetings into time slots otherwise allocated towards “scheduled free time” or toward a user completion of a to-do item. Different types of entries (meetings, scheduled free time, solitary tasks, personal time, etc.) can have different priorities and/or importance scores associated with them, which can prevent/permit non-owners from modifying pre-existing calendar entries. In one embodiment, a calendar owner can explicitly establish an importance score/access level for a given entry (as shown in interface  140 ). When entry specific settings are established, more generic settings such as category specific restrictions, can be superseded. 
         [0029]    Each of the entries of a calendar can have a set of associated access restrictions, which are handled by the entry restriction component  206 . A relationship engine  210  can determine a relationship between an entry owner and a user  224  attempting to access a calendar entry of the owner. Relationships can be based upon static considerations, handled by static module  212 , as well as dynamic considerations, handled by dynamic module  213 . Given a relationship, determined by engine  210 , a privilege engine  214  can determine a set of privileges that are to be granted based upon the relationship  214 . An access engine  216  can compare entry restrictions against user privileges, and can grant appropriate access to the calendar entries. Calendar server  202  can serve calendar entries to remotely located devices  220 /applications  222  based upon access rights established by access engine  216 . 
         [0030]    The server  202  can also include a data store  208 , which stores calendar entry information, user  224  profile information, security information, and the like, which is utilized by the calendar server  202 . The data store  208  can maintain multiple different tables, such as entry table  260 . Entry table  260  can store multiple different values for each calendar entry. Each entry  260  can include, for example, an entry identifier  262 , an entry type  263 , an entry category  264 , an entry time  265 , an associated calendar  266 , an owner  267 , and an entry specific access level  268 . These attributes  262 - 268  are for illustrative purposes only and are not to be construed as a limitation on the invention. 
         [0031]    The entry attribute  262  can represent a primary key that is unique for a calendar entry. An entry type  263  can include whether an entry is for an actual meeting, for a reminder, for a to-do item, and the like. An actual meeting can be a meeting that includes two or more people. A to-do item can include a time block set aside by a calendar owner to accomplish a task. A category  264  can represent a context to which the calendar entry applies, such as work, friends, hobby, family, and the like. The time  265  can be the time range/associated with the entry. The calendar  266  can be a foreign key that associates the entry with a specific calendar object. The owner  267  can be a person for whom the calendar entry  262  is maintained. The level  268  can refer to a restriction level associated with an individual entry. The level  268  can include a set of levels (low, average, high) or can be presented as a score or importance value associated with a related entry. The value of the level  268  can be compared against a relative privilege level (from engine  216 ) of a user  224  to determine what access rights a given user has against a particular calendar entry  262 . 
         [0032]    Users  224  can access the calendar server over network  230  using a client device  220 . The device can include an application  222  for interacting with the server  202 . The application  222  can be a client-side calendaring application and/or a Web browser that renders a Web application (served calendar, which includes a set of calendar entries). In one embodiment, one or more communication servers  240  can be used as communication intermediaries between the device  220  and the calendar server  202 . For example, a voice response system (provided by a communication server  240 ) can permit a user  224  to interact with a calendar server  202  via a telephony device and a voice user interface (VUI). The communication server  240  can also include an email server, an instant messaging server, and the like that communicates notifications to an owner when changes to the owner&#39;s calendar entries occur. 
         [0033]    In one embodiment, a relationship among users  224  can be based upon a strength of their relationship as determined by social networking interactions. For example, users  224  can exchange communications  254  stored in data store  252  using a social networking server  250 . This server  250  can be connected to the calendar server  202  via network  230 . More specifically, the dynamic module  213  of the relationship engine  210  can apply a set of rules to determine a relationship/relationship strength based upon data  254  stored and maintained by social networking server  250 . A relationship/relationship strength can also be based upon more static factors, such as a supervisory relationship within an organization hierarchy, a consanguinity or affinity (e.g., relationship by marriage) relationship, and the like, which can be handled by static module  212 . In one embodiment, static and dynamic factors can be combined into a hybrid relationship/relationship strength, which is used to determine a set of access rights to be granted to a given user  224  for a set of calendar entries of another. 
         [0034]      FIG. 3  is a flow chart of a method  300  for selectively sharing calendars in a collaborative computing space in accordance with an embodiment of the inventive arrangements disclosed herein. The method  300  can be performed in context of a system  200  or similar system. Method  300  shows two distinct processes, which can occur asynchronously; one being a process  310  for owner establishment of calendar entries and/or of owner configuration of access privileges for entries as well as configuration of calendaring system customizations; the other being a process  330  where a non-owner accesses/modifies an owner&#39;s calendar entries. 
         [0035]    Process  310  can begin in step  320 , where an owner enters a set of one or more calendar entries into their calendar. Each entry can be stored along with entry details, an entry type, and entry category, and other entry specific metadata, as shown in step  322 . In step  324 , the owner can optionally establish entry specific access restrictions for calendar entries that override “defaults” based upon entry type, category, or other metadata. In step  326 , the owner can configure behavior of the calendar application to customize relationship strength determinations, access privileges granted to others, change notification/alerting features for when others change entries in an owner&#39;s calendar, etc. In step  328 , a calendar server can save the entry specific data, the entry access restrictions, and the user customizations. Programmatic actions can be performed per entry to determine a set of access restrictions for each of the calendar entries, where these determinations are based upon programmatic rules driven by entry type, category, etc. Different access restrictions can apply to different users attempting to access the calendar entries based at least in part upon a relationship between the owner and the accessing user. 
         [0036]    Process  330  can begin in step  340 , where a user connects to a calendaring system and attempts to access calendar entries of another user, who is referred to as a calendar owner. In step  342 , a relationship between the user and the calendar owner can be determined. In step  344 , a relationship strength can be optionally calculated. The relationship strength/type can be based upon relative static and/or relatively dynamic factors. Static factors can include, for example, consanguinity bonds and legal family bonds and an relative placement/relationship within an organizational hierarchy (e.g., boss-subordinate relationships). Dynamic relationships can be based upon a frequency of contacts/strength, which can be determined based upon social networking techniques and communications. For example, a relationship strength of a “friendship” can be considered relatively strong when many communications are exchanged between two parties and considered relatively weak when few communications are exchanged. In step  346 , a set of access privileges for the user against the owner&#39;s calendar can be determined based upon the relationship/relationship strength. In step  348 , for each entry in the owner&#39;s calendar, the access privileges for the user can be compared against access restrictions for those entries and suitable privileges can be granted based upon comparison results. 
         [0037]    In one embodiment, communication/relationship content can be analyzed so that a relationship strength is evaluated within a specific context. For example, a strength of communications can be specific to a particular project, organization, hobby and the like, where outside of this context, a weaker relationship exists. These context can be compared against context of a related calendar entry (if the entry is for a hobby then a relationship strength will be based upon/biased for that hobby; if an entry is for a work project then a relationship strength will be based upon/biased for that project; etc.) A level of granularity and complexity used for determining relationship strength/context is arbitrary and will vary based upon implementation specific choices and goals. 
         [0038]    In step  350 , calendar entries and control options can be provided to the user/presented within an interface being used by the user which are consistent with the comparison results. In step  352 , the user can optionally add new entries to the owner&#39;s calendar. Some of the existing entries (depending upon granted privileges) can be changed/modified/replaced with the new entries. In step  354 , the owner&#39;s calendar can be adjusted to eliminate conflicts. For example, if a new entry conflicted with owner scheduled time to complete a task, the task completion time entry can be rescheduled/adjusted so that it does not conflict with the new entry. Owner configured settings can be optionally used, which dictate a manner in which the calendaring system performs conflict resolving adjustments. In step  356 , a calendar owner can be optionally notified of any changes made to their calendars. 
         [0039]    To illustrate process  330  using a concrete example, a non-owner can attempt to view an owner&#39;s calendar. The non-owner can be presented with entries showing busy-time, which is scheduled but still available to the non-owner (based upon strength of relationship between the non-owner and the owner). The non-owner can establish a new meeting with the owner in a slot at least partially labeled as busy-time. When the owner views his calendar, any non-owner meetings can be labeled as “pushed requests” to indicate that another has “pushed”a meeting into a time-slot that was previously occupied. A calendar owner can approve this new meeting, which can result in the busy-time being automatically rescheduled/canceled. 
         [0040]    The diagrams in  FIGS. 1-3  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 code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block 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 combinations of special purpose hardware and computer instructions. 
         [0041]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
         [0042]    The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form 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 invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.