code: def create_index_with_nan(self, closed="right"):
      mask = [True, False] + [True] * 8
      return IntervalIndex.from_arrays(
          np.where(mask, np.arange(10), np.nan),
          np.where(mask, np.arange(1, 11), np.nan),
          closed=closed,
      )
  
imports: from itertools import permutations
  import re
  import numpy
  import pytest
  import pandas
  from pandas import Index, Interval, IntervalIndex, Timedelta, Timestamp, date_range, interval_range, isna, notna, timedelta_range
  import pandas._testing
  import pandas.core.common
label_desc: Use image node_id 2 for calling the TestIntervalIndex obj's underlying member method code with example usage: obj.create_index_with_nan(closed) and returns: IntervalIndex