class_docstr: Disregards the value of the current trace (or observed data) and
  samples a value from the model's prior.
class_docstr_tok: ["Disregards","the","value","of","the","current","trace","(","or","observed","data",")","and","samples","a","value","from","the","model","'s","prior","."]
code: def setup(self, warmup_steps, data):
      self.data = data
      (
          init_params,
          potential_fn,
          transforms,
          model_trace,
      ) = initialize_model(self.model, model_args=(data,))
      if self._initial_params is None:
          self._initial_params = init_params
      if self.transforms is None:
          self.transforms = transforms
      self._prototype_trace = model_trace
  
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 2 for calling the PriorKernel obj's underlying member method code with example usage: obj.setup(warmup_steps, data) without return types