code: def testDefaultFitMultiple(self):
      N = 4
      params = [{self.estimator.fake: i} for i in range(N)]
      modelIter = self.estimator.fitMultiple(self.data, params)
      indexList = []
      for index, model in modelIter:
          self.assertEqual(model.getFake(), index)
          indexList.append(index)
      self.assertEqual(sorted(indexList), list(range(N)))
  
file_path: spark/python/pyspark/ml/tests/test_base.py
imports: import unittest
  from pyspark.sql.types import DoubleType, IntegerType
  from pyspark.testing.mlutils import MockDataset, MockEstimator, MockUnaryTransformer, MockTransformer, SparkSessionTestCase
label_desc: Use image node_id 3 for calling the EstimatorTest obj's underlying member method code with example usage: obj.testDefaultFitMultiple() without return types