code: func (i *IdLock) Get(id string) sync.Locker {
  	i.locksMu.Lock()
  	defer i.locksMu.Unlock()
  
  	var l sync.Locker
  	var ok bool
  
  	l, ok = i.locks[id]
  	if !ok {
  		l = &sync.Mutex{}
  		i.locks[id] = l
  	}
  
  	return l
  }
docs: // Get returns a lock that is bound to a specific id.