human
Here's a good function header given the following:
I wrote the below code

    mock_open = MagicMock(spec=open)
    mock_file = MagicMock(spec=file)
    @contextmanager
    def stub_open(*args, **kwargs):
        mock_open(*args, **kwargs)
        (yield mock_file)
    with patch('__builtin__.open', stub_open):
        (yield (mock_open, mock_file))

What's a good function header?
assistant
#Here's a good function header.

@contextmanager
def patch_open():