code: def test_shift() -> None:
      a = pl.Series("a", [1, 2, 3])
      assert_series_equal(a.shift(1), pl.Series("a", [None, 1, 2]))
      assert_series_equal(a.shift(-1), pl.Series("a", [2, 3, None]))
      assert_series_equal(a.shift(-2), pl.Series("a", [3, None, None]))
      assert_series_equal(
          a.shift(-1, fill_value=10), pl.Series("a", [2, 3, 10])
      )
  
file_path: polars/py-polars/tests/unit/operations/test_shift.py
imports: from __future__ import annotations
  from datetime import date
  import pytest
  import polars
  from polars.testing import assert_frame_equal, assert_series_equal
label_desc: Use image node_id 1 for calling a global function with example usage: test_shift() without return types