code: def test_single_observation(self):
      with pm.Model():
          p = pm.Uniform("p", 0, 1)
          pm.Binomial("w", p=p, n=2, observed=[1])
          inference_data = pm.sample(
              500,
              chains=2,
              return_inferencedata=True,
              idata_kwargs=dict(log_likelihood=True),
          )
  
      assert inference_data
      assert inference_data.log_likelihood["w"].shape == (2, 500, 1)
  
imports: import warnings
  from typing import Dict, Tuple
  import numpy
  import pytensor.tensor
  import pytest
  from arviz import InferenceData
  from arviz.tests.helpers import check_multiple_attrs
  from numpy import ma
  from pytensor.tensor.subtensor import AdvancedIncSubtensor, AdvancedIncSubtensor1
  import pymc
  from pymc.backends.arviz import InferenceDataConverter, predictions_to_inference_data, to_inference_data
  from pymc.exceptions import ImputationWarning
label_desc: Use image node_id 15 for calling the TestDataPyMC obj's underlying member method code with example usage: obj.test_single_observation() without return types