code: def get_bn(zero_init=False):
      """
      Zero init gamma is good for resnet. See https://arxiv.org/abs/1706.02677.
      """
      if zero_init:
          return lambda x, name=None: BatchNorm(
              "bn", x, gamma_initializer=tf.zeros_initializer()
          )
      else:
          return lambda x, name=None: BatchNorm("bn", x)
  
file_path: tensorpack/examples/ResNet/resnet_model.py
imports: import tensorflow
  from tensorpack import tfv1
  from tensorpack.models import BatchNorm, BNReLU, Conv2D, FullyConnected, GlobalAvgPooling, MaxPooling
  from tensorpack.tfutils.argscope import argscope, get_arg_scope
label_desc: Use image node_id 2 for calling a global function with example usage: get_bn(zero_init) and returns: function, function