Try implement filtering by model and receiver (problem in - (NSArray *)ordersSortedWithKey:(NSString *)aKey
                       ascending:(BOOL)anAscending
             includeActiveOrders:(BOOL)anActiveFlag
           includeArchivedOrders:(BOOL)anArchivedFlag
                   withRecievers:(NSArray *)recieverIDs
                      withModels:(NSArray *)modelIDs)