code: public JavaType create(ClassIndex index, ClassPlan plan) {
  
          // base class
          JavaInterfaceSource type = Roaster.parse(
                  JavaInterfaceSource.class,
                  "public interface " + plan.getClassName() + "Supplier<T extends " + plan.getClassName() + "> {}"
          );
  
          type.setPackage(plan.getPackageName());
  
          type.addAnnotation(FunctionalInterface.class);
  
          addGet( type, plan );
  
          return type;
      }
docs: Base template for a resource representation.
  Covers the resource attributes
  
  @param index
  @param plan
  @return