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 courses. * * @see Course * @see CourseAttributes */ public final class CoursesDb extends EntitiesDb<Course, CourseAttributes> { private static final CoursesDb instance = new CoursesDb(); private CoursesDb() { // prevent initialization } public static CoursesDb inst() { return instance; } /** * Gets a course. */ public CourseAttributes getCourse(String courseId) { assert courseId != null; return makeAttributesOrNull(getCourseEntity(courseId)); } /** * Gets a list of courses. */ public List<CourseAttributes> getCourses(List<String> courseIds) { assert courseIds != null; assert courseIds.toArray() != null; return makeAttributes(getCourseEntities(courseIds)); } /** * Updates a course by {@link CourseAttributes.UpdateOptions}. * * @return updated course * @throws InvalidParametersException if attributes to update are not valid * @throws EntityDoesNotExistException if the course cannot be found */ public CourseAttributes updateCourse(CourseAttributes.UpdateOptions updateOptions) throws InvalidParametersException, EntityDoesNotExistException { assert updateOptions != null; Course course = getCourseEntity(updateOptions.getCourseId()); if (course == null) { throw new EntityDoesNotExistException(ERROR_UPDATE_NON_EXISTENT); } CourseAttributes newAttributes = makeAttributes(course); newAttributes.update(updateOptions); newAttributes.sanitizeForSaving(); if (!newAttributes.isValid()) { throw new InvalidParametersException(newAttributes.getInvalidityInfo()); } // update only if change boolean hasSameAttributes = this.<String>hasSameValue(course.getName(), newAttributes.getName()) && this.<String>hasSameValue(course.getInstitute(), newAttributes.getInstitute()) && this.<String>hasSameValue(course.getTimeZone(), newAttributes.getTimeZone()); if (hasSameAttributes) { log.info(String.format(OPTIMIZED_SAVING_POLICY_APPLIED, Course.class.getSimpleName(), updateOptions)); return newAttributes; } course.setName(newAttributes.getName()); course.setTimeZone(newAttributes.getTimeZone()); course.setInstitute(newAttributes.getInstitute()); saveEntity(course); return makeAttributes(course); } /** * Deletes a course. */ public void deleteCourse(String courseId) { assert courseId != null; deleteEntity(Key.create(Course.class, courseId)); } /** * Soft-deletes a course by its given corresponding ID. * @return Soft-deletion time of the course. */ public Instant softDeleteCourse(String courseId) throws EntityDoesNotExistException { assert courseId != null; Course courseEntity = getCourseEntity(courseId); if (courseEntity == null) { throw new EntityDoesNotExistException(ERROR_UPDATE_NON_EXISTENT); } courseEntity.setDeletedAt(Instant.now()); saveEntity(courseEntity); return courseEntity.getDeletedAt(); } /** * Restores a soft-deleted course by its given corresponding ID. */ public void restoreDeletedCourse(String courseId) throws En
Assistant: