def test_coalesce(self):
     config = Config()
     assert config._coalesce(None, None, 1) == 1
 def test_coalesce_all_none(self):
     config = Config()
     assert config._coalesce(None, None, None) is None
 def test_coalesce_no_arguments(self):
     config = Config()
     assert config._coalesce() is None