code: public final ImmutableList<ObjectType> getImplementedInterfaces() {
      FunctionType superCtor = isConstructor() ? getSuperClassConstructor() : null;
      if (superCtor == null) {
        return implementedInterfaces;
      }
      ImmutableList.Builder<ObjectType> builder = ImmutableList.builder();
      builder.addAll(implementedInterfaces);
      while (superCtor != null) {
        builder.addAll(superCtor.implementedInterfaces);
        superCtor = superCtor.getSuperClassConstructor();
      }
      return builder.build();
    }
docs: Returns interfaces implemented directly by a class or its superclass.