code: def __call__(self, model, guide, *args):
      # On first call, initialize params and save their names.
      if self._param_trace is None:
          with block(), trace() as tr, block(
              hide_fn=lambda m: m["type"] != "param"
          ):
              elbo(model, guide, *args)
          self._param_trace = tr
  
      # Augment args with reads from the global param store.
      unconstrained_params = tuple(
          param(name).unconstrained() for name in self._param_trace
      )
      params_and_args = unconstrained_params + args
  
      # On first call, create a compiled elbo.
      if self._compiled is None:
  
          def compiled(*params_and_args):
              unconstrained_params = params_and_args[
                  : len(self._param_trace)
              ]
              args = params_and_args[len(self._param_trace) :]
              for name, unconstrained_param in zip(
                  self._param_trace, unconstrained_params
              ):
                  constrained_param = param(
                      name
                  )  # assume param has been initialized
                  assert (
                      constrained_param.unconstrained()
                      is unconstrained_param
                  )
                  self._param_trace[name]["value"] = constrained_param
              return replay(elbo, guide_trace=self._param_trace)(
                  model, guide, *args
              )
  
          with validation_enabled(False), warnings.catch_warnings():
              if self.ignore_jit_warnings:
                  warnings.filterwarnings(
                      "ignore", category=torch.jit.TracerWarning
                  )
              self._compiled = torch.jit.trace(
                  compiled, params_and_args, check_trace=False
              )
  
      return self._compiled(*params_and_args)
  
imports: import random
  import warnings
  import weakref
  from collections import OrderedDict
  import numpy
  import torch
  from pyro.distributions import validation_enabled
label_desc: Use image node_id 2 for calling the JitTrace_ELBO obj's underlying member method code with example usage: obj.__call__(model, guide) and returns: self, replay