code: func (v *FontDescription) GetUnsetFields(to_unset FontMask) {
  	C.pango_font_description_unset_fields(v.native(), (C.PangoFontMask)(to_unset))
  }
docs: //void          pango_font_description_unset_fields   (PangoFontDescription       *desc,
  //						     PangoFontMask               to_unset);