code: def test_environment_detector():
      # Default
      detector = EnvironmentDetector()
      envs = detector.detect()
      assert len(envs) == 0
  
      # Check if assertion succeeds
      detector.checks["always_true"] = lambda: True
      envs = detector.detect()
      assert len(envs) == 1 and envs[0] == "always_true"
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_environment_detector() without return types