code: def test_learn(self):
      # Test only some special cases which are probably not yet handled
      # like the metafeatures to eliminate and the random forest
      # hyperparameters
      self.meta_optimizer._learn()
  
file_path: auto-sklearn/test/test_metalearning/pyMetaLearn/test_metalearner.py
imports: import logging
  import os
  import numpy
  import pandas
  from ConfigSpace.configuration_space import Configuration
  import autosklearn.metalearning.optimizers.metalearn_optimizer.metalearner
  import autosklearn.pipeline.classification
  from autosklearn.metalearning.metalearning.meta_base import MetaBase
  import unittest
label_desc: Use image node_id 6 for calling the MetaLearnerTest obj's underlying member method code with example usage: obj.test_learn() without return types