def test_source_modified_unmodified(self):
     uowcommit, a1, b1, a_mapper, b_mapper = self._fixture()
     a1.obj().id = 10
     pairs = [(a_mapper.c.id, b_mapper.c.id,)]
     eq_(
         sync.source_modified(uowcommit, a1, a_mapper, pairs), 
         False
     )

 def test_source_modified_modified(self):
     uowcommit, a1, b1, a_mapper, b_mapper = self._fixture()
     a1.obj().id = 10
     a1.commit_all(a1.dict)
     a1.obj().id = 12
     pairs = [(a_mapper.c.id, b_mapper.c.id,)]
     eq_(
         sync.source_modified(uowcommit, a1, a_mapper, pairs), 
         True
     )

 def test_source_modified_composite_unmodified(self):
     uowcommit, a1, b1, a_mapper, b_mapper = self._fixture()
     a1.obj().foo = 10
     a1._commit_all(a1.dict)
     pairs = [(a_mapper.c.id, b_mapper.c.id,),
             (a_mapper.c.foo, b_mapper.c.id)]
     eq_(
         sync.source_modified(uowcommit, a1, a_mapper, pairs),
         False
     )

 def _pks_changed(self, uowcommit, state):
     return bool(state.key) and sync.source_modified(uowcommit, 
                                 state, 
                                 self.mapper, 
                                 self.prop.synchronize_pairs)

 def test_source_modified_no_pairs(self):
     uowcommit, a1, b1, a_mapper, b_mapper = self._fixture()
     eq_(
         sync.source_modified(uowcommit, a1, a_mapper, []), 
         False
     )

 def _pks_changed(self, uowcommit, state):
     return state.has_identity and sync.source_modified(uowcommit, 
                                 state, 
                                 self.mapper, 
                                 self.prop.synchronize_pairs)