code: def log_prob(self, x):
      return self._standard_gamma.log_prob(x * self.rate) + torch.log(
          self.rate
      )
  
imports: import torch
  from pyro.distributions.rejector import Rejector
  from pyro.distributions.score_parts import ScoreParts
  from pyro.distributions.torch import Beta, Dirichlet, Gamma, Normal
  from pyro.distributions.util import copy_docs_from, weakmethod
label_desc: Use image node_id 4 for calling the RejectionGamma obj's underlying member method code with example usage: obj.log_prob(x) and returns: unknown