public LibraryManagementService(IBookRepository bookRepository, IBookIssueRepository bookIssueRepository, IReturnBookRepository returnBookRepository, IStudentRepository studentRepository)
 {
     _bookRepository       = bookRepository;
     _bookIssueRepository  = bookIssueRepository;
     _returnBookRepository = returnBookRepository;
     _studentRepository    = studentRepository;
 }
 public BookIssueService(IBookIssueRepository bookIssueRepository)
 {
     _bookIssueRepository = bookIssueRepository;
 }