code: func (hdl *connHdl) disconnect() {
  	// silently ignore repeated calls to closed connections
  	if hdl.connected {
  		if e := hdl.conn.Close(); e != nil {
  			panic(fmt.Errorf("on connHdl.Close()", e))
  			//			return newSystemErrorWithCause( "on connHdl.Close()", e)
  		}
  		hdl.connected = false
  		// REVU - pretty please TODO do the customized log
  		//		log.Printf("<INFO> %s - DISCONNECTED", hdl)
  	}
  }
docs: // disconnects from net connections and sets connected state to false
  // panics on net error (with error)