void ICompletionWidget.SetCompletionText(CodeCompletionContext ctx, string partial_word, string complete_word)
        {
            int sp = editEntry.Position - partial_word.Length;

            editEntry.DeleteText(sp, sp + partial_word.Length);
            editEntry.InsertText(complete_word, ref sp);
            editEntry.Position = sp;             // sp is incremented by InsertText
        }