can i usea flutterflow widgets inside custom widgets?

I am looking ath teh code "generated" (witht he code inspector onUI). Is it possible to use it within a custom widget?

For example:
FlutterFlowIconButton(

borderColor: FlutterFlowTheme.of(context).primary,

borderRadius: 20,

borderWidth: 1,

buttonSize: 40,

fillColor: FlutterFlowTheme.of(context).accent1,

icon: Icon(

Icons.delete,

I tried to use but it complains:
The method 'FlutterFlowIconButton' isn't defined for the type '_NewCustomWidget3State'. Try correcting the name to the name of an existing method, or defining a method named 'FlutterFlowIconButton'.

Or there's an impórt missing (but which one and how to find). Thanks.