class_docstr: Assign anchors to ground-truth targets. Produces anchor classification
  labels and bounding-box regression targets.
class_docstr_tok: ["Assign","anchors","to","ground-truth","targets",".","Produces","anchor","classification","labels","and","bounding-box","regression","targets","."]
docstr: This layer does not propagate gradients.
docstr_tok: ["This","layer","does","not","propagate","gradients","."]
code: def backward(self, top, propagate_down, bottom):
      """This layer does not propagate gradients."""
      pass
  
file_path: CNTK/Examples/Image/Detection/utils/caffe_layers/anchor_target_layer.py
imports: import os
  import yaml
  import numpy
  import numpy.random
  from utils.caffe_layers.default_config import cfg
  from utils.rpn.generate_anchors import generate_anchors
  from utils.rpn.bbox_transform import bbox_transform
  from utils.cython_modules.cython_bbox import bbox_overlaps
label_desc: Use image node_id 5 for calling the AnchorTargetLayer obj's underlying member method code with example usage: obj.backward(top, propagate_down, bottom) without return types