code: def model(self, data):
      loc = self.loc_0
      lambda_prec = self.lambda_prec
      for i in range(1, self.chain_len + 1):
          loc = pyro.sample(
              "loc_{}".format(i),
              dist.Normal(loc=loc, scale=lambda_prec),
          )
      pyro.sample("obs", dist.Normal(loc, lambda_prec), obs=data)
  
imports: import logging
  import os
  from collections import namedtuple
  import pytest
  import torch
  import pyro
  import pyro.distributions
  from pyro.infer.mcmc import NUTS
  from pyro.infer.mcmc.api import MCMC
  from pyro.infer.mcmc.hmc import HMC
  from tests.common import assert_close, assert_equal
label_desc: Use image node_id 2 for calling the GaussianChain obj's underlying member method code with example usage: obj.model(data) without return types