code: func (n *node) get(key Item) Item {
  	i, found := n.items.find(key)
  	if found {
  		return n.items[i]
  	} else if len(n.children) > 0 {
  		return n.children[i].get(key)
  	}
  	return nil
  }
docs: // get finds the given key in the subtree and returns it.