Description
Some test cases have been disabled in the places as shown below because of pandas nondeterministic return values:
- pandas returns `None` or `nan` randomly
python/pyspark/pandas/tests/test_series.py test_astype
- pandas returns `True` or `False` randomly
python/pyspark/pandas/tests/indexes/test_base.py test_monotonic
We should revisit them later.