code: def conditional(self, *args, **kwargs):
      self._conditional = _conditional(dist.Poisson, parent=self)(
          *args, **kwargs
      )
      return self._conditional
  
imports: from collections import defaultdict
  import torch
  import pyro.distributions
  from pyro import poutine
  from pyro.distributions.util import sum_leftmost
  from pyro.poutine.messenger import Messenger
  from pyro.poutine.util import site_is_subsample
label_desc: Use image node_id 3 for calling the GammaPoissonPair obj's underlying member method code with example usage: obj.conditional() and returns: self