class_docstr: ResNet model builder. It builds a ResNet like network backbone without
  lateral connection (C2D, I3D, Slow).
  
  Christoph Feichtenhofer, Haoqi Fan, Jitendra Malik, and Kaiming He.
  "SlowFast networks for video recognition."
  https://arxiv.org/pdf/1812.03982.pdf
  
  Xiaolong Wang, Ross Girshick, Abhinav Gupta, and Kaiming He.
  "Non-local neural networks."
  https://arxiv.org/pdf/1711.07971.pdf
class_docstr_tok: ["ResNet","model","builder",".","It","builds","a","ResNet","like","network","backbone","without","lateral","connection","(","C2D",",","I3D",",","Slow",")",".","Christoph","Feichtenhofer",",","Haoqi","Fan",",","Jitendra","Malik",",","and","Kaiming","He",".","``","SlowFast","networks","for","video","recognition",".","''","https",":","\/\/arxiv.org\/pdf\/1812.03982.pdf","Xiaolong","Wang",",","Ross","Girshick",",","Abhinav","Gupta",",","and","Kaiming","He",".","``","Non-local","neural","networks",".","''","https",":","\/\/arxiv.org\/pdf\/1711.07971.pdf"]
code: def forward(self, x, bboxes=None):
      x = x[:]  # avoid pass by reference
      x = self.s1(x)
      x = self.s2(x)
      y = (
          []
      )  # Don't modify x list in place due to activation checkpoint.
      for pathway in range(self.num_pathways):
          pool = getattr(self, "pathway{}_pool".format(pathway))
          y.append(pool(x[pathway]))
      x = self.s3(y)
      x = self.s4(x)
      x = self.s5(x)
      if self.enable_detection:
          x = self.head(x, bboxes)
      else:
          x = self.head(x)
      return x
  
imports: import math
  from functools import partial
  import torch
  import torch.nn
  import torch.nn.functional
  from torch.nn.init import trunc_normal_
  import slowfast.utils.logging
  import slowfast.utils.weight_init_helper
  from slowfast.models.attention import MultiScaleBlock
  from slowfast.models.batchnorm_helper import get_norm
  from slowfast.models.common import TwoStreamFusion
  from slowfast.models.reversible_mvit import ReversibleMViT
  from slowfast.models.utils import calc_mvit_feature_geometry, get_3d_sincos_pos_embed, round_width, validate_checkpoint_wrapper_import
  from .None import head_helper, operators, resnet_helper, stem_helper
  from .build import MODEL_REGISTRY
label_desc: Use image node_id 3 for calling the ResNet obj's underlying member method code with example usage: obj.forward(x, bboxes) and returns: x