code: func (l *lNode) lookup(e *Entry) (interface{}, bool) {
  	found, ok := l.Find(func(sn interface{}) bool {
  		return bytes.Equal(e.Key, sn.(*sNode).Key)
  	})
  	if !ok {
  		return nil, false
  	}
  	return found.(*sNode).Value, true
  }
docs: // lookup returns the value at the given entry in the L-node or returns false
  // if it's not contained.