code: func (entries Entries) max() (uint64, bool) {
  	if len(entries) == 0 {
  		return 0, false
  	}
  
  	return entries[len(entries)-1].Key(), true
  }
docs: // max returns the value of the highest key in this list
  // of entries.  The bool indicates if it's a valid key, that
  // is if there is more than zero entries in this list.