code: def event_shape(self):
      return torch.Size()
  
file_path: pyro/pyro/distributions/testing/rejection_exponential.py
imports: import torch
  from torch.distributions.utils import broadcast_all
  import pyro.distributions.constraints
  from pyro.distributions.rejector import Rejector
  from pyro.distributions.torch import Exponential
  from pyro.distributions.util import copy_docs_from, weakmethod
label_desc: Use image node_id 4 for calling the RejectionExponential obj's underlying member method code with example usage: obj.event_shape() and returns: torch