code: def test_dummy_classifier():
      """Test function for DummyClassifier."""
      X_train, y_train = load_unit_test(
          split="train", return_type="numpy3D"
      )
      X_test, _ = load_unit_test(split="test", return_type="numpy3D")
      dummy = DummyClassifier()
      dummy.fit(X_train, y_train)
      pred = dummy.predict(X_test)
      assert all(i == "1" for i in pred)
      pred_proba = dummy.predict_proba(X_test)
      assert all(np.array_equal([0.5, 0.5], i) for i in pred_proba)
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_dummy_classifier() without return types