code: def test_merge_stats_with_self(self):
      stats = StatCounter([1.0, 2.0, 3.0, 4.0])
      stats.mergeStats(stats)
      self.assertEqual(stats.count(), 8)
      self.assertEqual(stats.max(), 4.0)
      self.assertEqual(stats.mean(), 2.5)
      self.assertEqual(stats.min(), 1.0)
      self.assertAlmostEqual(stats.stdev(), 1.118033988749895)
      self.assertAlmostEqual(stats.sampleStdev(), 1.1952286093343936)
      self.assertEqual(stats.sum(), 20.0)
      self.assertAlmostEqual(stats.variance(), 1.25)
      self.assertAlmostEqual(stats.sampleVariance(), 1.4285714285714286)
  
file_path: spark/python/pyspark/tests/test_statcounter.py
imports: import math
  from pyspark.statcounter import StatCounter
  from pyspark.testing.utils import ReusedPySparkTestCase
label_desc: Use image node_id 6 for calling the StatCounterTests obj's underlying member method code with example usage: obj.test_merge_stats_with_self() without return types