class_docstr: Loss carried out lazily to avoid unnecessary communication
code: def backward(self):
      self.z.backward(self.dz / self.dz.share.shape[0])
  
imports: import typing
  import torch
  from fate.arch.context import Context
  from fate.arch.protocol.mpc.common.encoding import IgnoreEncodings
  from fate.arch.protocol.mpc.mpc import FixedPointEncoder
  from fate.arch.trace import auto_trace
label_desc: Use image node_id 3 for calling the SSHESSHELinearRegressionLossLayerLazyLoss obj's underlying member method code with example usage: obj.backward() without return types