'.. http:put:: /channels/subscribed/(string: channelid)
Subscribe to a specific channel. Returns error 409 if you are already subscribed to this channel.
**Example request**:
.. sourcecode:: none
curl -X PUT http://localhost:8085/channels/subscribed/da69aaad39ccf468aba2ab9177d5f8d8160135e6
**Example response**:
.. sourcecode:: javascript
"subscribed" : True
:statuscode 409: (conflict) if you are already subscribed to the specified channel.'

def render_PUT(self, request):

    request.setHeader('Content-Type', 'text/json')
    channel_info = self.get_channel_from_db(self.cid)
    if ((channel_info is not None) and (channel_info[7] == VOTE_SUBSCRIBE)):
        request.setResponseCode(http.CONFLICT)
        return json.dumps({'error': ALREADY_SUBSCRIBED_RESPONSE_MSG})
    def on_vote_done(_):
        request.write(json.dumps({'subscribed': True}))
        request.finish()
    def on_vote_error(failure):
        request.processingFailed(failure)
    self.vote_for_channel(self.cid, VOTE_SUBSCRIBE).addCallback(on_vote_done).addErrback(on_vote_error)
    return NOT_DONE_YET
