code: func (t *Collection) GetTotals() (numItems uint64, numBytes uint64, err error) {
  	rnl := t.rootAddRef()
  	defer t.rootDecRef(rnl)
  	n := rnl.root
  	nNode, err := n.read(t.store)
  	if err != nil || n.isEmpty() || nNode == nil {
  		return 0, 0, err
  	}
  	return nNode.numNodes, nNode.numBytes, nil
  }
docs: // Returns total number of items and total key bytes plus value bytes.