code: def start(self):
          
          super(BitstampWSS, self).start()
  
          self.pusher = pusherclient.Pusher(self.addr, **self.__pusher_options)
          self.pusher.connection.bind('pusher:connection_established',
                                      self._register_bindings)
          self.pusher.connect()
docs: Extension of Pusher.connect() method, which registers all callbacks with
          the relevant channels, before initializing a connection.
          :return: