code: @Override
      public DeletePermissionPolicyResult deletePermissionPolicy(DeletePermissionPolicyRequest request) {
          request = beforeClientExecution(request);
          return executeDeletePermissionPolicy(request);
      }
docs: <p>
  Permanently deletes an IAM policy from the specified RuleGroup.
  </p>
  <p>
  The user making the request must be the owner of the RuleGroup.
  </p>
  
  @param deletePermissionPolicyRequest
  @return Result of the DeletePermissionPolicy operation returned by the service.
  @throws WAFInternalErrorException
  The operation failed because of a system problem, even though the request was valid. Retry your request.
  @throws WAFStaleDataException
  The operation failed because you tried to create, update, or delete an object by using a change token
  that has already been used.
  @throws WAFNonexistentItemException
  The operation failed because the referenced object doesn't exist.
  @sample AWSWAFRegional.DeletePermissionPolicy
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/waf-regional-2016-11-28/DeletePermissionPolicy"
  target="_top">AWS API Documentation</a>