code: @Transactional
      public void delete(E entity) {
          if (entityManager.contains(entity)) {
              entityManager.remove(entity);
          } else {
              // could be a delete on a transient instance
              E entityRef = entityManager.getReference(type, entity.getId());
  
              if (entityRef != null) {
                  entityManager.remove(entityRef);
              } else {
                  log.warning("Attempt to delete an instance that is not present in the database: " + entity);
              }
          }
      }
docs: Delete the given entity E from the repository.
  
  @param entity the entity to be deleted.