code: func (e *Engine) Open() error {
  	e.initTrackers()
  
  	if err := os.MkdirAll(e.path, 0777); err != nil {
  		return err
  	}
  
  	if err := e.cleanup(); err != nil {
  		return err
  	}
  
  	if err := e.WAL.Open(); err != nil {
  		return err
  	}
  
  	if err := e.FileStore.Open(); err != nil {
  		return err
  	}
  
  	if err := e.reloadCache(); err != nil {
  		return err
  	}
  
  	e.Compactor.Open()
  
  	if e.enableCompactionsOnOpen {
  		e.SetCompactionsEnabled(true)
  	}
  
  	return nil
  }
docs: // Open opens and initializes the engine.