docstr: It should not be possible to create an isolated node in the network
code: def test_do_on_node_with_no_effects_not_allowed(
      self, train_model, train_data_idx
  ):
      """It should not be possible to create an isolated node in the network"""
  
      bn = BayesianNetwork(train_model)
      bn.fit_node_states(train_data_idx).fit_cpds(train_data_idx)
  
      ie = InferenceEngine(bn)
  
      with pytest.raises(
          ValueError,
          match="Do calculus cannot be applied because it would result in an isolate",
      ):
          ie.do_intervention("a", 1)
  
imports: import math
  import pytest
  from causalnex.inference import InferenceEngine
  from causalnex.network import BayesianNetwork
  from causalnex.structure import StructureModel
  from causalnex.structure.notears import from_pandas
label_desc: Use image node_id 8 for calling the TestInferenceEngineIdx obj's underlying member method code with example usage: obj.test_do_on_node_with_no_effects_not_allowed(train_model, train_data_idx) without return types