code: func (v *TextView) GetLineYrange(iter *TextIter) (y, height int) {
  	var yx, heightx C.gint
  	C.gtk_text_view_get_line_yrange(v.native(), iter.native(), &yx, &heightx)
  	return int(yx), int(heightx)
  }
docs: // GetLineYrange is a wrapper around gtk_text_view_get_line_yrange().