code: def backbone_forward(self, image, coord_features=None):
      raise NotImplementedError
  
imports: import os
  import sys
  import paddle
  import paddle.nn
  import numpy
  from inference.ops import DistMaps3D, ScaleLayer, BatchImageNormalize3D
  from paddleseg.utils import utils
label_desc: Use image node_id 4 for calling the ISModel3D obj's underlying member method code with example usage: obj.backbone_forward(image, coord_features) without return types