code: def test_variance_when_size_zero(self):
      # SPARK-38854: Test case to improve test coverage when
      # StatCounter argument is empty list or None
      arguments = [[], None]
  
      for arg in arguments:
          stats = StatCounter(arg)
          self.assertTrue(math.isnan(stats.variance()))
          self.assertTrue(math.isnan(stats.sampleVariance()))
          self.assertEqual(stats.count(), 0)
          self.assertTrue(math.isinf(stats.max()))
          self.assertTrue(math.isinf(stats.min()))
          self.assertEqual(stats.mean(), 0.0)
  
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 5 for calling the StatCounterTests obj's underlying member method code with example usage: obj.test_variance_when_size_zero() without return types