@abc.abstractmethod<EOL><INDENT>def write_stream(self, stream):<DEDENT>
pass<EOL>
Writes a stream to this stream.

        :param stream: an input stream
        :type stream: ``osid.transport.DataInputStream``
        :raise: ``IllegalState`` -- this stream has been closed
        :raise: ``NullArgument`` -- ``stream`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request

        *compliance: mandatory -- This method must be implemented.*