code: def test_string_classes(self):
      np.random.seed(0)
      clf = LogisticRegression()
      plot_learning_curve(
          clf, self.X, convert_labels_into_string(self.y)
      )
  
imports: from __future__ import absolute_import
  import unittest
  from sklearn.datasets import load_iris
  from sklearn.linear_model import LogisticRegression
  from sklearn.ensemble import RandomForestClassifier
  import numpy
  import matplotlib.pyplot
  from scikitplot.estimators import plot_feature_importances
  from scikitplot.estimators import plot_learning_curve
label_desc: Use image node_id 3 for calling the TestPlotLearningCurve obj's underlying member method code with example usage: obj.test_string_classes() without return types