def is_hybi00(headers):
    """
    Determine whether a given set of headers is HyBi-00-compliant.

    Hixie-76 and HyBi-00 use a pair of keys in the headers to handshake with
    servers.
    """
    return 'Sec-WebSocket-Key1' in headers and 'Sec-WebSocket-Key2' in headers
