def METHOD_NAME(file_contents_dict):
    """Create a mock "open" that will mock open multiple files based on name
    Args:
        file_contents_dict: A dict of 'fname': 'content'
    Returns:
        A Mock opener that will return the supplied content if name is in
        file_contents_dict, otherwise the builtin open
    """
    mock_files = {}
    for fname, content in file_contents_dict.items():
        mock_files[fname] = mock_open(read_data=content).return_value
    def my_open(fname, *args, **kwargs):
        if fname in mock_files:
            return mock_files[fname]
        else:
            return builtin_open(fname, *args, **kwargs)
    mock_opener = mock.Mock()
    mock_opener.side_effect = my_open
    return mock_opener