code: def test_datetime64_tz_dropna(self, unit):
      # DatetimeLikeBlock
      ser = Series(
          [
              Timestamp("2011-01-01 10:00"),
              NaT,
              Timestamp("2011-01-03 10:00"),
              NaT,
          ],
          dtype=f"M8[{unit}]",
      )
      result = ser.dropna()
      expected = Series(
          [
              Timestamp("2011-01-01 10:00"),
              Timestamp("2011-01-03 10:00"),
          ],
          index=[0, 2],
          dtype=f"M8[{unit}]",
      )
      tm.assert_series_equal(result, expected)
  
      # DatetimeTZBlock
      idx = DatetimeIndex(
          ["2011-01-01 10:00", NaT, "2011-01-03 10:00", NaT],
          tz="Asia/Tokyo",
      ).as_unit(unit)
      ser = Series(idx)
      assert ser.dtype == f"datetime64[{unit}, Asia/Tokyo]"
      result = ser.dropna()
      expected = Series(
          [
              Timestamp("2011-01-01 10:00", tz="Asia/Tokyo"),
              Timestamp("2011-01-03 10:00", tz="Asia/Tokyo"),
          ],
          index=[0, 2],
          dtype=f"datetime64[{unit}, Asia/Tokyo]",
      )
      assert result.dtype == f"datetime64[{unit}, Asia/Tokyo]"
      tm.assert_series_equal(result, expected)
  
file_path: pandas/pandas/tests/series/methods/test_dropna.py
imports: import numpy
  import pytest
  from pandas import DatetimeIndex, IntervalIndex, NaT, Period, Series, Timestamp
  import pandas._testing
label_desc: Use image node_id 6 for calling the TestDropna obj's underlying member method code with example usage: obj.test_datetime64_tz_dropna(unit) without return types