'Call this to deliver raw audio data to be played.
If the buffer is :class:`None`, the end-of-stream token is put on the
playbin. We will get a GStreamer message when the stream playback
reaches the token, and can then do any end-of-stream related tasks.
Note that the URI must be set to ``appsrc://`` for this to work.
Returns :class:`True` if data was delivered.
:param buffer_: buffer to pass to appsrc
:type buffer_: :class:`Gst.Buffer` or :class:`None`
:rtype: boolean'

def emit_data(self, buffer_):

    return self._appsrc.push(buffer_)
