@Override
  public void prepare(Policy policy, boolean update) {
    validateRules(policy);
  }
  ...
  public void validateRules(Policy policy) {
    List<Rule> rules = policy.getRules();
    if (nullOrEmpty(rules)) {
      throw new IllegalArgumentException(CatalogExceptionMessage.EMPTY_RULES_IN_POLICY);
    }

    // Validate all the expressions in the rule
    for (Rule rule : rules) {
      CompiledRule.validateExpression(rule.getCondition(), Boolean.class);
      rule.getResources().sort(String.CASE_INSENSITIVE_ORDER);
      rule.getOperations().sort(Comparator.comparing(MetadataOperation::value));

      // Remove redundant resources
      rule.setResources(filterRedundantResources(rule.getResources()));

      // Remove redundant operations
      rule.setOperations(filterRedundantOperations(rule.getOperations()));
    }
    rules.sort(Comparator.comparing(Rule::getName));
  }

public Response createOrUpdate(UriInfo uriInfo, SecurityContext securityContext, T entity) {
  repository.prepareInternal(entity, true);

  // If entity does not exist, this is a create operation, else update operation
  ResourceContext<T> resourceContext = getResourceContextByName(entity.getFullyQualifiedName());
  MetadataOperation operation = createOrUpdateOperation(resourceContext);
  OperationContext operationContext = new OperationContext(entityType, operation);
  if (operation == CREATE) {
    CreateResourceContext<T> createResourceContext = new CreateResourceContext<>(entityType, entity);
    authorizer.authorize(securityContext, operationContext, createResourceContext);
    entity = addHref(uriInfo, repository.create(uriInfo, entity));
    return new PutResponse<>(Response.Status.CREATED, entity, RestUtil.ENTITY_CREATED).toResponse();
  }
  authorizer.authorize(securityContext, operationContext, resourceContext);
  PutResponse<T> response = repository.createOrUpdate(uriInfo, entity);
  addHref(uriInfo, response.getEntity());
  return response.toResponse();
}

@PUT
@Operation(
    operationId = "createOrUpdatePolicy",
    summary = "Create or update a policy",
    description = "Create a new policy, if it does not exist or update an existing policy.",
    responses = {
      @ApiResponse(
          responseCode = "200",
          description = "The policy",
          content = @Content(mediaType = "application/json", schema = @Schema(implementation = Policy.class))),
      @ApiResponse(responseCode = "400", description = "Bad request")
    })
public Response createOrUpdate(
    @Context UriInfo uriInfo, @Context SecurityContext securityContext, @Valid CreatePolicy create) {
  Policy policy = getPolicy(create, securityContext.getUserPrincipal().getName());
  return createOrUpdate(uriInfo, securityContext, policy);
}