code: def test_diff_dt64(self):
      # datetime diff (GH#3100)
      ser = Series(date_range("20130102", periods=5))
      result = ser.diff()
      expected = ser - ser.shift(1)
      tm.assert_series_equal(result, expected)
  
      # timedelta diff
      result = result - result.shift(1)  # previous result
      expected = expected.diff()  # previously expected
      tm.assert_series_equal(result, expected)
  
file_path: pandas/pandas/tests/series/methods/test_diff.py
imports: import numpy
  import pytest
  from pandas import Series, TimedeltaIndex, date_range
  import pandas._testing
label_desc: Use image node_id 5 for calling the TestSeriesDiff obj's underlying member method code with example usage: obj.test_diff_dt64() without return types