code: def test_group_difference(explainer):
      """Check that the group_difference plot is unchanged."""
      np.random.seed(0)
  
      shap_values = explainer(explainer.data).values
      group_mask = np.random.randint(2, size=shap_values.shape[0])
      feature_names = explainer.data_feature_names
      fig, ax = plt.subplots()
      shap.plots.group_difference(
          shap_values, group_mask, feature_names, show=False, ax=ax
      )
      plt.tight_layout()
      return fig
  
imports: import matplotlib.pyplot
  import numpy
  import pytest
  import shap
label_desc: Use image node_id 1 for calling a global function with example usage: test_group_difference(explainer) and returns: fig