code: func FlowBoxNew() (*FlowBox, error) {
  	c := C.gtk_flow_box_new()
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	return wrapFlowBox(glib.Take(unsafe.Pointer(c))), nil
  }
docs: // FlowBoxNew is a wrapper around gtk_flow_box_new()