public CharSegment toLowerCase(){
  char[] buffer=_buffer;
  int len=_length;
  int offset=_offset;
  while (--len >= 0)   buffer[offset + len]=Character.toLowerCase(buffer[offset + len]);
  return this;
}

public CharSegment toLowerCase ( ) { char [ ] buffer = _buffer ; int len = _length ; int offset = _offset ; while ( -- len >= 0 ) buffer [ offset + len ] = Character . toLowerCase ( buffer [ offset + len ] ) ; return this ; }
converts the contents of the segment to lower case .
