setLineCap method
Set line starting and ending cap type
Implementation
void setLineCap(PdfLineCap cap) {
  assert(() {
    if (_page.settings.verbose) {
      _buf.putString(' ' * (_indent));
    }
    return true;
  }());
  _buf.putString('${cap.index} J ');
  assert(() {
    if (_page.settings.verbose) {
      _buf.putString(' ' * (_commentIndent - 4 - _indent));
      _buf.putComment('setLineCap(${cap.name})');
    }
    return true;
  }());
}