code: def opened(self):
          
          # give up if there are no more ddp versions to try
          if self._ddp_version_index == len(DDP_VERSIONS):
              self.ddpsocket._debug_log('* DDP VERSION MISMATCH')
              self.emit('version_mismatch', DDP_VERSIONS)
              return
  
          # use server recommended version if we support it
          if self._retry_new_version in DDP_VERSIONS:
              self._ddp_version_index = [i for i, x in enumerate(DDP_VERSIONS)
                                         if x == self._retry_new_version][0]
  
          connect_msg = {
              "msg": "connect",
              "version": DDP_VERSIONS[self._ddp_version_index],
              "support": DDP_VERSIONS
          }
  
          # if we've already got a session token then reconnect
          if self._session:
              connect_msg["session"] = self._session
  
          self.send(connect_msg)
docs: Send the connect message to the server.