code: def test_pindex_fieldaccessor_nat(self):
      idx = PeriodIndex(
          ["2011-01", "2011-02", "NaT", "2012-03", "2012-04"],
          freq="D",
          name="name",
      )
  
      exp = Index(
          [2011, 2011, -1, 2012, 2012], dtype=np.int64, name="name"
      )
      tm.assert_index_equal(idx.year, exp)
      exp = Index([1, 2, -1, 3, 4], dtype=np.int64, name="name")
      tm.assert_index_equal(idx.month, exp)
  
file_path: pandas/pandas/tests/indexes/period/test_period.py
imports: import numpy
  import pytest
  from pandas import Index, NaT, Period, PeriodIndex, Series, date_range, offsets, period_range
  import pandas._testing
label_desc: Use image node_id 6 for calling the TestPeriodIndex obj's underlying member method code with example usage: obj.test_pindex_fieldaccessor_nat() without return types