code: def backbone_forward(self, image, coord_features=None):
      backbone_features = self.feature_extractor(
          image, coord_features
      )  # todo ：增加对点特征的融合
  
      return {
          "instances": backbone_features,
          "instances_aux": backbone_features,
      }
  
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 2 for calling the VNetModel obj's underlying member method code with example usage: obj.backbone_forward(image, coord_features) and returns: dict