code: def test_get_conn_returns_a_boto3_connection(self):
      hook = StepFunctionHook(aws_conn_id="aws_default")
      assert (
          "stepfunctions"
          == hook.get_conn().meta.service_model.service_name
      )
  
imports: from __future__ import annotations
  from moto import mock_stepfunctions
  from airflow.providers.amazon.aws.hooks.step_function import StepFunctionHook
label_desc: Use image node_id 1 for calling the TestStepFunctionHook obj's underlying member method code with example usage: obj.test_get_conn_returns_a_boto3_connection() without return types