code: func (v *SpinButton) GetAdjustment() *Adjustment {
  	c := C.gtk_spin_button_get_adjustment(v.native())
  	if c == nil {
  		return nil
  	}
  	return wrapAdjustment(glib.Take(unsafe.Pointer(c)))
  }
docs: // GetAdjustment() is a wrapper around gtk_spin_button_get_adjustment