code: def _plot_overlap(ax, x_grid, y_min):
      """Plot the overlap region."""
      highlight_color = [0.95, 0.90, 0.40]
      (line,) = ax.plot(
          x_grid, y_min, color=highlight_color, lw=8, label="overlap"
      )
      line.zorder -= 1
  
file_path: fairlearn/fairlearn/postprocessing/_plotting.py
imports: from sklearn.utils.validation import check_is_fitted
  from ._constants import _MATPLOTLIB_IMPORT_ERROR_MESSAGE
  from ._threshold_optimizer import ThresholdOptimizer
label_desc: Use image node_id 3 for calling a global function with example usage: _plot_overlap(ax, x_grid, y_min) without return types