code: def test_get_conn_fallback_to_default_azure_credential_when_schema_is_not_provided(
      self, mock_connection, mock_default_azure_credential
  ):
      mock_connection.return_value = self.mock_conn_without_schema
      hook = MessageHook(azure_service_bus_conn_id=self.conn_id)
      assert isinstance(hook.get_conn(), ServiceBusClient)
      assert mock_default_azure_credential.called_with(
          managed_identity_client_id=None,
          workload_identity_tenant_id=None,
      )
  
imports: from __future__ import annotations
  from unittest import mock
  import pytest
  from airflow.models import Connection
  from airflow.providers.microsoft.azure.hooks.asb import AdminClientHook, MessageHook
label_desc: Use image node_id 3 for calling the TestMessageHook obj's underlying member method code with example usage: obj.test_get_conn_fallback_to_default_azure_credential_when_schema_is_not_provided(mock_connection, mock_default_azure_credential) without return types