what are the benefits of using base Interface in c# -

i m working application in base inteface has been created below

public interface ibaserepository : idisposable {     bool isunitofwork { get; set; }      void savechanges(); } 

then other interfaces extend interface as

public interface icourserepository : ibaserepository {     course getcoursebyid(int id);      list<course> getcourses();      coursemodule getcoursemodulebyid(int id);  } 

just wondering advantage of approach

the base repository allows specify behavior want repository contracts have without repeating in every imyentityrepository create.

even more fun though implementing base repository , specifying generic code generic operations:

public abstract class baserepository<tentity> : irepository<tentity> tentity : class {      private dbcontext _context;      public repository(dbcontext context) {         if (context == null) {             throw new argumentnullexception("context");         }         _context = context;     }     protected dbcontext dbcontext { { return _context; } }      public void create(tentity entity) {         if (entity == null) {             throw new argumentnullexception("entity");         }         dbcontext.set<tentity>().add(entity);         dbcontext.savechanges();     }      public tentity getbyid(int id) {         return dbcontext.set<tentity>().find(id);     }      public void delete(tentity entity) {         if (entity == null) {             throw new argumentnullexception("entity");         }         dbcontext.set<tentity>().attach(entity);         dbcontext.set<tentity>().remove(entity);         dbcontext.savechanges();     }      public void update(tentity entity) {         if (entity == null) {             throw new argumentnullexception("entity");         }         dbcontext.set<tentity>().attach(entity);         dbcontext.entry(entity).state = entitystate.modified;         dbcontext.savechanges();     } 

etc., have myentityreporitory extend baserepository