code: def heartbeat_interval(self, heartbeat_interval_ms):
          
  
          assert issubclass(heartbeat_interval_ms.__class__, int)
  
          return self.__push('heartbeat_interval', heartbeat_interval_ms)
docs: heartbeat_interval (nsqd 0.2.19+) milliseconds between heartbeats.
  
          Valid range: 1000 <= heartbeat_interval <= configured_max (-1 disables 
          heartbeats)
  
          --max-heartbeat-interval (nsqd flag) controls the max
  
          Defaults to --client-timeout / 2