public IEnumerator <NSRange> GetEnumerator()
        {
            var position = _range.StartIndex;

            Completion.Change(position);

            while (position < _range.EndIndex)
            {
                var misspelled = _textChecker.RangeOfMisspelledWordInString(_plainText,
                                                                            new NSRange(0, _plainText.Length), position, false, "ru_RU");

                if (misspelled.Location == NSRange.NotFound)
                {
                    Completion.MarkCompleted();

                    yield break;
                }

                yield return(misspelled);

                position = (int)misspelled.Location + (int)misspelled.Length + 1;

                Completion.Change(position);
            }

            Completion.MarkCompleted();
        }