code: func (yfast *YFastTrie) Insert(entries ...Entry) Entries {
  	overwritten := make(Entries, 0, len(entries))
  	for _, e := range entries {
  		overwritten = append(overwritten, yfast.insert(e))
  	}
  
  	return overwritten
  }
docs: // Insert will insert the provided entries into the y-fast trie
  // and return a list of entries that were overwritten.