def __init__(self, protocol: Protocol) -> None:
        ''' Configure a Receiver with a specific Bokeh protocol.

        Args:
            protocol (Protocol) :
                A Bokeh protocol object to use to assemble collected message
                fragments.
        '''
        self._protocol = protocol
        self._current_consumer = self._HEADER  # type: ignore[assignment] # https://github.com/python/mypy/issues/2427
        self._message = None
        self._partial = None
        self._buf_header = None