def METHOD_NAME(self):
    a = ContextMock(name='A')
    b = ContextMock(name='B')
    a.__enter__ = Mock(name='A.__enter__')
    b.__enter__ = Mock(name='B.__enter__')
    with self.c._consume_from(a, b):
        pass
    a.__enter__.assert_called_with()
    b.__enter__.assert_called_with()