class_docstr: BBox head for `SCNet <https://arxiv.org/abs/2012.10150>`_.
  
  This inherits ``ConvFCBBoxHead`` with modified forward() function, allow us
  to get intermediate shared feature.
docstr: Forward function.
  
  Args:
      x (Tensor): input features
      return_shared_feat (bool): If True, return cls-reg-shared feature.
  
  Return:
      out (tuple[Tensor]): contain ``cls_score`` and ``bbox_pred``,
          if  ``return_shared_feat`` is True, append ``x_shared`` to the
          returned tuple.
code: def forward(
      self, x: Tensor, return_shared_feat: bool = False
  ) -> Union[Tensor, Tuple[Tensor]]:
      """Forward function.
  
      Args:
          x (Tensor): input features
          return_shared_feat (bool): If True, return cls-reg-shared feature.
  
      Return:
          out (tuple[Tensor]): contain ``cls_score`` and ``bbox_pred``,
              if  ``return_shared_feat`` is True, append ``x_shared`` to the
              returned tuple.
      """
      x_shared = self._forward_shared(x)
      out = self._forward_cls_reg(x_shared)
  
      if return_shared_feat:
          out += (x_shared,)
  
      return out
  
file_path: mmdetection/mmdet/models/roi_heads/bbox_heads/scnet_bbox_head.py
imports: from typing import Tuple, Union
  from torch import Tensor
  from mmdet.registry import MODELS
  from .convfc_bbox_head import ConvFCBBoxHead
label_desc: Use image node_id 3 for calling the SCNetBBoxHead obj's underlying member method code with example usage: obj.forward(x, return_shared_feat) and returns: out