code: def test_sample_examples_no_train_instances(self):
      adapter_spec = AdapterSpec(
          method=ADAPT_MULTIPLE_CHOICE_JOINT,
          model="openai/ada",
          max_train_instances=2,
      )
      adapter = AdapterFactory.get_adapter(
          adapter_spec, self.tokenizer_service
      )
      examples = adapter.sample_examples(all_train_instances=[], seed=0)
      assert len(examples) == 0
  
file_path: H2O/h2o_hf/helm/src/helm/benchmark/adaptation/adapters/test_multiple_choice_joint_adapter.py
imports: from helm.benchmark.scenarios.scenario import Instance, Input, Output, Reference, CORRECT_TAG
  from helm.benchmark.adaptation.adapter_spec import AdapterSpec
  from .adapter_factory import AdapterFactory, ADAPT_MULTIPLE_CHOICE_JOINT
  from .test_adapter import TestAdapter
label_desc: Use image node_id 2 for calling the TestMultipleChoiceJointAdapter obj's underlying member method code with example usage: obj.test_sample_examples_no_train_instances() without return types