code: def plot_contours(ax, clf, xx, yy, **params):
      Z = clf.predict(np.c_[xx.ravel(), yy.ravel()])
      Z = Z.reshape(xx.shape)
      out = ax.contourf(xx, yy, Z, **params)
      return out
  
imports: import json
  import os
  import numpy
  import joblib
  import matplotlib.pyplot
  from data_util import load_data
label_desc: Use image node_id 2 for calling a global function with example usage: plot_contours(ax, clf, xx, yy) and returns: out