code: def test_null_sum_streaming_10455() -> None:
      df = pl.DataFrame(
          {
              "x": [1] * 10,
              "y": [None] * 10,
          },
          schema={"x": pl.Int64, "y": pl.Float32},
      )
      result = df.lazy().group_by("x").sum().collect(streaming=True)
      expected = {"x": [1], "y": [0.0]}
      assert result.to_dict(as_series=False) == expected
  
imports: from __future__ import annotations
  import os
  import tempfile
  import time
  from datetime import date
  from pathlib import Path
  from typing import TYPE_CHECKING, Any
  import numpy
  import pytest
  import polars
  from polars.exceptions import PolarsInefficientMapWarning
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 15 for calling a global function with example usage: test_null_sum_streaming_10455() without return types