code: def test_raw_function():
      """Make sure passing a simple masking function works."""
  
      X, _ = shap.datasets.california(n_points=500)
  
      def test(X):
          return np.sum(X, 1)
  
      def custom_masker(mask, x):
          return (x * mask).reshape(
              1, len(x)
          )  # just zero out the features we are masking
  
      explainer = shap.Explainer(test, custom_masker)
      shap_values = explainer(X[:100])
  
      assert np.var(shap_values.values - shap_values.data) < 1e-6
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_raw_function() and returns: np, unknown