System.Xml.XmlTextReaderImpl.ParseUnexpectedToken C# (CSharp) Method

        private string ParseUnexpectedToken()
        {
            if (_ps.charPos == _ps.charsUsed)
            {
                return null;
            }
            if (_xmlCharType.IsNCNameSingleChar(_ps.chars[_ps.charPos]))
            {
                int pos = _ps.charPos + 1;
                while (_xmlCharType.IsNCNameSingleChar(_ps.chars[pos]))
                {
                    pos++;
                }
                return new string(_ps.chars, _ps.charPos, pos - _ps.charPos);
            }
            else
            {
                Debug.Assert(_ps.charPos < _ps.charsUsed);
                return new string(_ps.chars, _ps.charPos, 1);
            }
        }