code: def test_asof_join_sorted_by_group(capsys: Any) -> None:
      df1 = pl.DataFrame(
          {
              "key": ["a", "a", "a", "b", "b", "b"],
              "asof_key": [2.0, 1.0, 3.0, 1.0, 2.0, 3.0],
              "a": [102, 101, 103, 104, 105, 106],
          }
      ).sort(by=["key", "asof_key"])
  
      df2 = pl.DataFrame(
          {
              "key": ["a", "a", "a", "b", "b", "b"],
              "asof_key": [0.9, 1.9, 2.9, 0.9, 1.9, 2.9],
              "b": [201, 202, 203, 204, 205, 206],
          }
      ).sort(by=["key", "asof_key"])
  
      expected = pl.DataFrame(
          [
              pl.Series(
                  "key", ["a", "a", "a", "b", "b", "b"], dtype=pl.String
              ),
              pl.Series(
                  "asof_key",
                  [1.0, 2.0, 3.0, 1.0, 2.0, 3.0],
                  dtype=pl.Float64,
              ),
              pl.Series(
                  "a", [101, 102, 103, 104, 105, 106], dtype=pl.Int64
              ),
              pl.Series(
                  "b", [201, 202, 203, 204, 205, 206], dtype=pl.Int64
              ),
          ]
      )
  
      out = df1.join_asof(df2, on="asof_key", by="key")
      assert_frame_equal(out, expected)
  
      _, err = capsys.readouterr()
      assert "is not explicitly sorted" not in err
  
imports: from datetime import date, datetime, timedelta
  from typing import Any
  import numpy
  import pytest
  import polars
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 13 for calling a global function with example usage: test_asof_join_sorted_by_group(capsys) without return types