code: func (m *MemoryStorer) StartCleaner() {
  	if m.maxAge == 0 || m.cleanInterval == 0 {
  		panic("both max age and clean interval must be set to non-zero")
  	}
  
  	// init quit chan
  	m.quit = make(chan struct{})
  
  	m.wg.Add(1)
  
  	// Start the cleaner infinite loop go routine.
  	// StopCleaner() can be used to kill this go routine.
  	go m.cleanerLoop()
  }
docs: // StartCleaner starts the memory session cleaner go routine. This go routine
  // will delete expired sessions from the memory map on the cleanInterval interval.