code: def test_gradcheck(self):
      ...
  
imports: from functools import partial
  import pytest
  import torch
  from kornia.contrib.models.rt_detr.architecture.hgnetv2 import PPHGNetV2
  from kornia.contrib.models.rt_detr.architecture.hybrid_encoder import HybridEncoder, RepVggBlock
  from kornia.contrib.models.rt_detr.architecture.resnet_d import ResNetD
  from kornia.contrib.models.rt_detr.architecture.rtdetr_head import RTDETRHead
  from kornia.contrib.models.rt_detr.model import RTDETR, RTDETRConfig
  from kornia.testing import BaseTester, assert_close
label_desc: Use image node_id 4 for calling the TestRTDETR obj's underlying member method code with example usage: obj.test_gradcheck() without return types