internal override long GetChars(long dataIndex, char[] buffer, int bufferIndex, int length) {
if (_s == null)
return 0;
if (buffer == null)
return _s.Length;
int actualLength = ((dataIndex + length) >= _s.Length) ? (_s.Length - (int)dataIndex) : length;
_s.CopyTo((int)dataIndex, buffer, bufferIndex, actualLength);
return actualLength;
}