docs: protected void appendFunctionalInterfaceAnnotation(JvmGenericType type) {
  		if (type != null && Utils.isFunctionalInterface(type, this.sarlSignatureProvider)
  				&& this.annotationFinder.findAnnotation(type, FunctionalInterface.class) == null) {
  			addAnnotationSafe(type, FunctionalInterface.class);
  		}
  	}