code: func (fb *FlowBox) GetChildAtIndex(idx int) *FlowBoxChild {
  	c := C.gtk_flow_box_get_child_at_index(fb.native(), C.gint(idx))
  	if c == nil {
  		return nil
  	}
  	return wrapFlowBoxChild(glib.Take(unsafe.Pointer(c)))
  }
docs: // GetChildAtIndex is a wrapper around gtk_flow_box_get_child_at_index()