guesses the content type with libmagic if available
    :param func_:
    :param args:
    :param kwargs:
    :return:

def wrap_guess_content_type(func_, *args, **kwargs):
    """
    guesses the content type with libmagic if available
    :param func_:
    :param args:
    :param kwargs:
    :return:
    """
    assert isinstance(args[0], dict)
    if not args[0].get(CONTENTTYPE_FIELD, None):
        content = args[0].get(CONTENT_FIELD, b"")
        try:
            args[0][CONTENTTYPE_FIELD] = magic.from_buffer(content)
        except magic.MagicException:  # pragma: no cover
            args[0][CONTENTTYPE_FIELD] = MockMagic.DEFAULT_MAGIC
    return func_(*args, **kwargs)