code: def r3d(rgb=False, flow=False, pretrained=False, progress=True):
      """Get R3D_18 models."""
      r3d_rgb = r3d_flow = None
      if rgb:
          r3d_rgb = r3d_18_rgb(pretrained=pretrained, progress=progress)
      if flow:
          r3d_flow = r3d_18_flow(
              pretrained=pretrained, progress=progress
          )
      models = {"rgb": r3d_rgb, "flow": r3d_flow}
      return models
  
imports: import torch.nn
  from torch.hub import load_state_dict_from_url
label_desc: Use image node_id 9 for calling a global function with example usage: r3d(rgb, flow, pretrained, progress) and returns: models