code: def inv_var_reg(self, net, reg):
      log_k = net.NextScopedBlob("log_k")
      net.Log(self.k, log_k)
      net.Scale(log_k, reg, scale=-0.5)
  
file_path: pytorch/caffe2/python/layers/adaptive_weight.py
imports: import numpy
  from caffe2.python import core, schema
  from caffe2.python.layers.layers import ModelLayer
  from caffe2.python.regularizer import BoundedGradientProjection, LogBarrier
label_desc: Use image node_id 8 for calling the AdaptiveWeight obj's underlying member method code with example usage: obj.inv_var_reg(net, reg) without return types