code: def test_comparison_nulls_single() -> None:
      df1 = pl.DataFrame(
          {
              "a": pl.Series([None], dtype=pl.String),
              "b": pl.Series([None], dtype=pl.Int64),
              "c": pl.Series([None], dtype=pl.Boolean),
          }
      )
      df2 = pl.DataFrame(
          {
              "a": pl.Series([None], dtype=pl.String),
              "b": pl.Series([None], dtype=pl.Int64),
              "c": pl.Series([None], dtype=pl.Boolean),
          }
      )
      assert (df1 == df2).row(0) == (None, None, None)
      assert (df1 != df2).row(0) == (None, None, None)
  
imports: from __future__ import annotations
  import math
  from contextlib import nullcontext
  from typing import Any, ContextManager
  import pytest
  import polars
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 2 for calling a global function with example usage: test_comparison_nulls_single() without return types