'Same as on_send, but callback will get this stream as first argument
Callback will be passed three arguments::
callback(stream, msg, status)
Useful when a single callback should be used with multiple streams.'

def on_send_stream(self, callback):

    if (callback is None):
        self.stop_on_send()
    else:
        self.on_send((lambda msg, status: callback(self, msg, status)))
