default: {    addStudentsToCourse(        students: (
string | { email: string })
[],        courseId: number,    ): Promise<void>;    addUserToCourse(userId: number, courseId: number): Promise<ResultSetHeader>;    checkStudentExistingGroup(        userId: number,        courseId: number,    ): Promise<null | { group_id: number; group_name: string }>;    getStudentsByCourse(courseId: number): Promise<RowDataPacket[]>;    getUserCountByCourse(courseId: number): Promise<number>;    getUserCourses(userId: number): Promise<WorkLogCourseUser[]>;    removeUserFromCourse(        userId: number,        courseId: number,    ): Promise<ResultSetHeader>;    validateUserCourseAccess(        userId: number,        courseId: number,    ): Promise<boolean>;} = ... Type declaration
- addStudentsToCourse:function- addStudentsToCourse(    students:-  ( string | { email: string }- ) [],    courseId: number,): Promise<void>
 - Parameters- students: (string | { email: string })[]
- courseId: number
 
- Returns Promise<void>
 
- addUserToCourse:function- addUserToCourse(userId: number, courseId: number): Promise<ResultSetHeader> - Parameters- userId: number
- courseId: number
 
- Returns Promise<ResultSetHeader>
 
- checkStudentExistingGroup:function- checkStudentExistingGroup(    userId: number,    courseId: number,): Promise<null | { group_id: number; group_name: string }> - Parameters- userId: number
- courseId: number
 
- Returns Promise<null | { group_id: number; group_name: string }>
 
- getStudentsByCourse:function- getStudentsByCourse(courseId: number): Promise<RowDataPacket[]> - Returns Promise<RowDataPacket[]>
 
- getUserCountByCourse:function- getUserCountByCourse(courseId: number): Promise<number> 
 
- getUserCourses:function
- removeUserFromCourse:function- removeUserFromCourse(userId: number, courseId: number): Promise<ResultSetHeader> - Parameters- userId: number
- courseId: number
 
- Returns Promise<ResultSetHeader>
 
- validateUserCourseAccess:function- validateUserCourseAccess(userId: number, courseId: number): Promise<boolean> - Parameters- userId: number
- courseId: number
 
- Returns Promise<boolean>