code: def test_ensure_datetime64ns_bigendian():
      # GH#29684
      arr = np.array([np.datetime64(1, "ms")], dtype=">M8[ms]")
      result = astype_overflowsafe(arr, dtype=np.dtype("M8[ns]"))
  
      expected = np.array([np.datetime64(1, "ms")], dtype="M8[ns]")
      tm.assert_numpy_array_equal(result, expected)
  
file_path: pandas/pandas/tests/tslibs/test_conversion.py
imports: from datetime import datetime
  import numpy
  import pytest
  from pytz import UTC
  from pandas._libs.tslibs import OutOfBoundsTimedelta, astype_overflowsafe, conversion, iNaT, timezones, tz_convert_from_utc, tzconversion
  from pandas import Timestamp, date_range
  import pandas._testing
label_desc: Use image node_id 9 for calling a global function with example usage: test_ensure_datetime64ns_bigendian() without return types