code: def test_array_strptime_resolution_all_nat(self):
      arr = np.array([NaT, np.nan], dtype=object)
  
      fmt = "%Y-%m-%d %H:%M:%S"
      res, _ = array_strptime(
          arr, fmt=fmt, utc=False, creso=creso_infer
      )
      assert res.dtype == "M8[s]"
  
      res, _ = array_strptime(arr, fmt=fmt, utc=True, creso=creso_infer)
      assert res.dtype == "M8[s]"
  
file_path: pandas/pandas/tests/tslibs/test_strptime.py
imports: from datetime import datetime, timezone
  import numpy
  import pytest
  from pandas._libs.tslibs.dtypes import NpyDatetimeUnit
  from pandas._libs.tslibs.strptime import array_strptime
  from pandas import NaT, Timestamp
  import pandas._testing
label_desc: Use image node_id 1 for calling the TestArrayStrptimeResolutionInference obj's underlying member method code with example usage: obj.test_array_strptime_resolution_all_nat() without return types