code: func (db *DB) Load(rd io.Reader) error {
  	db.mu.Lock()
  	defer db.mu.Unlock()
  	if db.persist {
  		// cannot load into databases that persist to disk
  		return ErrPersistenceActive
  	}
  	return db.readLoad(rd, time.Now())
  }
docs: // Load loads commands from reader. This operation blocks all reads and writes.
  // Note that this can only work for fully in-memory databases opened with
  // Open(":memory:").