code: def _empty_model():
      return torch.tensor(1)
  
imports: import os
  from functools import partial
  import pytest
  import torch
  import pyro
  import pyro.distributions
  from pyro import poutine
  from pyro.infer.mcmc import HMC, NUTS
  from pyro.infer.mcmc.api import MCMC, StreamingMCMC, _MultiSampler, _UnarySampler
  from pyro.infer.mcmc.mcmc_kernel import MCMCKernel
  from pyro.infer.mcmc.util import initialize_model, select_samples
  from pyro.ops.streaming import StackStats, StatsOfDict
  from pyro.util import optional
  from tests.common import assert_close
label_desc: Use image node_id 6 for calling a global function with example usage: _empty_model() and returns: torch