code: def test_where_tz(self):
      i = date_range("20130101", periods=3, tz="US/Eastern")
      result = i.where(notna(i))
      expected = i
      tm.assert_index_equal(result, expected)
  
      i2 = i.copy()
      i2 = Index([pd.NaT, pd.NaT] + i[2:].tolist())
      result = i.where(notna(i2))
      expected = i2
      tm.assert_index_equal(result, expected)
  
imports: from datetime import date, datetime, time, timedelta
  import numpy
  import pytest
  from pandas._libs import index
  from pandas.compat.numpy import np_long
  import pandas
  from pandas import DatetimeIndex, Index, Timestamp, bdate_range, date_range, notna
  import pandas._testing
  from pandas.tseries.frequencies import to_offset
label_desc: Use image node_id 5 for calling the TestWhere obj's underlying member method code with example usage: obj.test_where_tz() without return types