def is_hop_by_hop_header(header):
    """Check if a header is an HTTP/1.1 "Hop-by-Hop" header.

    .. versionadded:: 0.5

    :param header: the header to test.
    :return: `True` if it's an entity header, `False` otherwise.
    """
    return header.lower() in _hop_by_hop_headers
dataset/ETHPy150Open Eforcers/gae-flask-todo/lib/werkzeug/http.py/is_hop_by_hop_header/original