'Computes the value for the Sec-WebSocket-Accept header,
given the value for Sec-WebSocket-Key.'

@staticmethod
def compute_accept_value(key):

    sha1 = hashlib.sha1()
    sha1.update(utf8(key))
    sha1.update('258EAFA5-E914-47DA-95CA-C5AB0DC85B11')
    return native_str(base64.b64encode(sha1.digest()))
