@abc.abstractmethod<EOL><INDENT>def send_request(self, request, callback):<DEDENT>
pass<EOL>
Sends data to the remote transport endpoint and sends the response to the callback.

        :param request: the request
        :type request: ``osid.transport.Request``
        :param callback: callback for the response
        :type callback: ``osid.transport.MessageReceiver``
        :raise: ``NullArgument`` -- ``request`` or ``callback`` is null
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unsupported`` -- ``request`` is not supported

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