Creates an instance of GradeHistoryService.
The Angular HttpClient for making API requests
Retrieves the complete grade history for a specific student.
The email address of the student
An Observable with the grade history entries for the student
Retrieves the complete grade history for all students taught by a specific teacher.
The email address of the teacher
An Observable with the grade history entries for all students taught by the teacher
Service responsible for retrieving grade history information from the server. Provides methods to access the audit trail of grade changes for students and teachers.