code: def test_output():
      """Tests basic ``Output`` methods."""
      my_output = Output()
  
      assert my_output.transform("test") == "test"
  
      my_output.transform = Mock()
      my_output("test")
      my_output.transform.assert_called_once()
  
imports: from unittest.mock import Mock
  import pytest
  from flash.core.data.io.output import Output
  from flash.core.utilities.imports import _TOPIC_CORE_AVAILABLE
label_desc: Use image node_id 1 for calling a global function with example usage: test_output() without return types