code: def test_forward_loss(self, device):
      if device == "cuda":
          if not torch.cuda.is_available():
              return unittest.skip("test requires GPU and torch+cuda")
  
      double_bbox_head = DoubleConvFCBBoxHead(
          num_convs=4,
          num_fcs=2,
          in_channels=1,
          conv_out_channels=4,
          fc_out_channels=4,
      )
      double_bbox_head = double_bbox_head.to(device=device)
  
      num_samples = 4
      feats = torch.rand((num_samples, 1, 7, 7)).to(device)
      double_bbox_head(x_cls=feats, x_reg=feats)
  
imports: import unittest
  from unittest import TestCase
  import torch
  from parameterized import parameterized
  from mmdet.models.roi_heads.bbox_heads import DoubleConvFCBBoxHead
label_desc: Use image node_id 1 for calling the TestDoubleBboxHead obj's underlying member method code with example usage: obj.test_forward_loss(device) and returns: unittest