code: def test_sklearn_plotting(self):
      from sklearn import datasets
  
      iris = datasets.load_iris()
  
      classifier = xgb.XGBClassifier()
      classifier.fit(iris.data, iris.target)
  
      import matplotlib
  
      matplotlib.use("Agg")
  
      from matplotlib.axes import Axes
      from graphviz import Digraph
  
      ax = xgb.plot_importance(classifier)
      assert isinstance(ax, Axes)
      assert ax.get_title() == "Feature importance"
      assert ax.get_xlabel() == "F score"
      assert ax.get_ylabel() == "Features"
      assert len(ax.patches) == 4
  
      g = xgb.to_graphviz(classifier, num_trees=0)
      assert isinstance(g, Digraph)
  
      ax = xgb.plot_tree(classifier, num_trees=0)
      assert isinstance(ax, Axes)
  
file_path: turicreate/src/external/xgboost/tests/python/test_basic.py
imports: import numpy
  import xgboost
  import unittest
  import matplotlib
label_desc: Use image node_id 11 for calling the TestBasic obj's underlying member method code with example usage: obj.test_sklearn_plotting() without return types