code: func (snap *dbCacheSnapshot) Get(key []byte) []byte {
  	// Check the cached entries first.
  	if snap.pendingRemove.Has(key) {
  		return nil
  	}
  	if value := snap.pendingKeys.Get(key); value != nil {
  		return value
  	}
  
  	// Consult the database.
  	value, err := snap.dbSnapshot.Get(key, nil)
  	if err != nil {
  		return nil
  	}
  	return value
  }
docs: // Get returns the value for the passed key.  The function will return nil when
  // the key does not exist.