Assistant: 
User: 
    Please analyze the following code file and determine whether it belongs to any of the provided modules based on the listed module descriptions.
    Note that the provided list of modules may not be exhaustive, and some files may not belong to any of the modules. 
    If the code belongs to a module, Only output the module name, without any explanation or additional information; otherwise, return 'None' if it does not belong to any module.

    Modules : {
        "UI": "Handles the front-end user interface, consisting of HTML, CSS, and JavaScript files generated by the Angular framework. It processes user requests and interacts with the server using AJAX for data retrieval and client-side interactions."
"Test Driver": "Facilitates automated regression testing and handles transmission of test data in JSON format. It performs Java testing using TestNG and JavaScript unit-testing with Jest. It also sets up a simulated web server for servlet-level tests and automates end-to-end testing using Selenium Java."
"Logic": "Manages the business logic of TEAMMATES, including handling relationships between entities, managing transactions, input value sanitization, access control rights, and interfacing with GAE-provided or third-party APIs."
"Storage": "Performs CRUD operations on data entities, validation of data, and abstraction of GQL queries, hiding the complexities of datastore from the Logic component."
"Common": "Contains utility classes, custom exceptions, and data transfer objects used across the entire application for easy consolidation and transfer of structured data."
"E2E": "Handles end-to-end testing and load & performance testing, providing helpers, abstractions of browser pages, and test cases for E2E tests and L&P tests."
"Client": "Contains scripts for administrative tasks, such as migrating data to a new schema and calculating statistics. This module connects directly to the application back-end for administrative purposes."
    }

    Code: package teammates.storage.api; /** * Handles CRUD operations for students. * * @see CourseStudent * @see StudentAttributes */ public final class StudentsDb extends EntitiesDb<CourseStudent, StudentAttributes> { private static final Logger log = Logger.getLogger(); private static final int MAX_KEY_REGENERATION_TRIES = 10; private static final StudentsDb instance = new StudentsDb(); private StudentsDb() { // prevent initialization } public static StudentsDb inst() { return instance; } private StudentSearchManager getSearchManager() { return SearchManagerFactory.getStudentSearchManager(); } /** * Creates or updates search document for the given student. */ public void putDocument(StudentAttributes student) throws SearchServiceException { getSearchManager().putDocument(student); } /** * Searches for students. * * @param instructors the constraint that restricts the search result */ public List<StudentAttributes> search(String queryString, List<InstructorAttributes> instructors) throws SearchServiceException { if (queryString.trim().isEmpty()) { return new ArrayList<>(); } return getSearchManager().searchStudents(queryString, instructors); } /** * Searches all students in the system. * * <p>This method should be used by admin only since the searching does not restrict the * visibility according to the logged-in user's google ID. This is used by admin to * search instructors in the whole system. */ public List<StudentAttributes> searchStudentsInWholeSystem(String queryString) throws SearchServiceException { if (queryString.trim().isEmpty()) { return new ArrayList<>(); } return getSearchManager().searchStudents(queryString, null); } /** * Removes search document for the given student by using {@code studentUniqueId}. */ public void deleteDocumentByStudentId(String studentUniqueId) { getSearchManager().deleteDocuments(Collections.singletonList(studentUniqueId)); } /** * Regenerates the registration key of a student in a course. * * @return the updated student * @throws EntityAlreadyExistsException if a new registration key could not be generated */ public StudentAttributes regenerateEntityKey(StudentAttributes originalStudent) throws EntityAlreadyExistsException { int numTries = 0; while (numTries < MAX_KEY_REGENERATION_TRIES) { CourseStudent updatedEntity = convertToEntityForSaving(originalStudent); if (!updatedEntity.getRegistrationKey().equals(originalStudent.getKey())) { saveEntity(updatedEntity); return makeAttributes(updatedEntity); } numTries++; } log.severe("Failed to generate new registration key for student after " + MAX_KEY_REGENERATION_TRIES + " tries"); throw new EntityAlreadyExistsException("Could not regenerate a new course registration key for the student."); } /** * Checks if the given students exist in the given course. */ public boolean hasExistingStudentsInCourse(String courseId, Collection<String> studentEmailAddresses) { if (studentEmailAddresses.
Assistant: