code: func (f *Fpdf) TransformEnd() {
  	if f.transformNest > 0 {
  		f.transformNest--
  		f.out("Q")
  	} else {
  		f.err = fmt.Errorf("error attempting to end transformation operation out of sequence")
  	}
  }
docs: // TransformEnd applies a transformation that was begun with a call to TransformBegin().
  //
  // The TransformBegin() example demonstrates this method.