code: def test_diff_all_int_dtype(self, any_int_numpy_dtype):
      # GH 14773
      df = DataFrame(range(5))
      df = df.astype(any_int_numpy_dtype)
      result = df.diff()
      expected_dtype = (
          "float32"
          if any_int_numpy_dtype in ("int8", "int16")
          else "float64"
      )
      expected = DataFrame(
          [np.nan, 1.0, 1.0, 1.0, 1.0], dtype=expected_dtype
      )
      tm.assert_frame_equal(result, expected)
  
imports: import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Series, Timestamp, date_range
  import pandas._testing
label_desc: Use image node_id 23 for calling the TestDataFrameDiff obj's underlying member method code with example usage: obj.test_diff_all_int_dtype(any_int_numpy_dtype) without return types