code: def regularize_cost_from_collection(name="regularize_cost"):
      """
      Get the cost from the regularizers in ``tf.GraphKeys.REGULARIZATION_LOSSES``.
      If in replicated mode, will only regularize variables created within the current tower.
  
      Args:
          name (str): the name of the returned tensor
  
      Returns:
          tf.Tensor: a scalar, the total regularization cost.
      """
      ctx = get_current_tower_context()
      if not ctx.is_training:
          # TODO Currently cannot build the wd_cost correctly at inference,
          # because ths vs_name used in inference can be '', therefore the
          # variable filter will fail
          return tf.constant(0, dtype=tf.float32, name="empty_" + name)
  
      # NOTE: this collection doesn't always grow with towers.
      # It only grows with actual variable creation, but not get_variable call.
      if (
          ctx.has_own_variables
      ):  # be careful of the first tower (name='')
          losses = ctx.get_collection_in_tower(
              tfv1.GraphKeys.REGULARIZATION_LOSSES
          )
      else:
          losses = tfv1.get_collection(
              tfv1.GraphKeys.REGULARIZATION_LOSSES
          )
      if len(losses) > 0:
          logger.info(
              "regularize_cost_from_collection() found {} regularizers "
              "in REGULARIZATION_LOSSES collection.".format(len(losses))
          )
  
          def maploss(l):
              assert l.dtype.is_floating, l
              if l.dtype != tf.float32:
                  l = tf.cast(l, tf.float32)
              return l
  
          losses = [maploss(l) for l in losses]
          reg_loss = tf.add_n(losses, name=name)
          return reg_loss
      else:
          return tf.constant(0, dtype=tf.float32, name="empty_" + name)
  
file_path: tensorpack/tensorpack/models/regularize.py
imports: import re
  import tensorflow
  from ..compat import tfv1
  from ..tfutils.common import get_tf_version_tuple
  from ..tfutils.tower import get_current_tower_context
  from ..utils import logger
  from ..utils.argtools import graph_memoized
  from .common import layer_register
label_desc: Use image node_id 3 for calling a global function with example usage: regularize_cost_from_collection(name) and returns: tf, reg_loss, tf, l