code: def test_where(self, listlike_box):
      klass = listlike_box
  
      idx = IntervalIndex.from_breaks(range(11), closed="right")
      cond = [True] * len(idx)
      expected = idx
      result = expected.where(klass(cond))
      tm.assert_index_equal(result, expected)
  
      cond = [False] + [True] * len(idx[1:])
      expected = IntervalIndex([np.nan] + idx[1:].tolist())
      result = idx.where(klass(cond))
      tm.assert_index_equal(result, expected)
  
imports: import re
  import numpy
  import pytest
  from pandas.errors import InvalidIndexError
  from pandas import NA, CategoricalIndex, DatetimeIndex, Index, Interval, IntervalIndex, MultiIndex, NaT, Timedelta, Timestamp, array, date_range, interval_range, isna, period_range, timedelta_range
  import pandas._testing
label_desc: Use image node_id 1 for calling the TestWhere obj's underlying member method code with example usage: obj.test_where(listlike_box) without return types