code: def _make_transition(num_output_features):
      out = nn.HybridSequential()
      out.add(nn.BatchNorm())
      out.add(nn.Activation("relu"))
      out.add(
          nn.Conv2D(num_output_features, kernel_size=1, use_bias=False)
      )
      out.add(nn.AvgPool2D(pool_size=2, strides=2))
      return out
  
file_path: mxnet/python/mxnet/gluon/model_zoo/vision/densenet.py
imports: import os
  from ....device import cpu
  from ...block import HybridBlock
  from ...None import nn
  from ....None import base
  from ....util import use_np, wrap_ctx_to_device_func
label_desc: Use image node_id 3 for calling a global function with example usage: _make_transition(num_output_features) and returns: out