def METHOD_NAME(self, filename, filename_info, filetype_info):
    """Mimic reader input file content.
    Args:
        filename (str): input filename
        filename_info (dict): Dict of metadata pulled from filename
        filetype_info (dict): Dict of metadata from the reader's yaml config for this file type
    Returns: dict of file content with keys like:
        - 'dataset'
        - '/attr/global_attr'
        - 'dataset/attr/global_attr'
        - 'dataset/shape'
    """
    raise NotImplementedError("Fake File Handler subclass must implement 'get_test_content'")