code: private boolean checkValidClass(Class<?> clazz) {
          return clazz.isAnnotationPresent(Entity.class) || clazz.isAnnotationPresent(MappedSuperclass.class)
              || clazz.isAnnotationPresent(Embeddable.class);
  
      }
docs: checks for a valid entity definition
  
  @param clazz
  @return