code: def test_diff():
      df = pd.DataFrame({"A": [9, 4, 2, 1]})
      data_id, column_type = "1", "diff"
      build_data_inst({data_id: df})
  
      cfg = {"col": "A", "periods": "1"}
      builder = ColumnBuilder(data_id, column_type, "dA", cfg)
      verify_builder(
          builder,
          lambda col: col.isnull().sum() == 1 and col.sum() == -8,
      )
  
imports: import numpy
  import pandas
  import pytest
  import sklearn
  from numpy.random import randn
  from pkg_resources import parse_version
  from six import PY3
  import dtale.pandas_util
  from dtale.column_builders import ColumnBuilder, ZERO_STD_ERROR
  from tests.dtale import build_data_inst
label_desc: Use image node_id 14 for calling a global function with example usage: test_diff() without return types