code: def test_negative_sample():
      df = pd.DataFrame(
          {
              "user_id": [1, 1, 2, 2, 3],
              "item_id": ["a", "b", "b", "c", "a"],
              "label": [1, 1, 1, 1, 1],
          }
      )
  
      df_with_samples = negative_sample(
          df, "user_id", "item_id", "label"
      )
  
      assert 9 <= len(df_with_samples) <= 10
      assert df_with_samples["label"].sum() == 5
  
      # Check data types
      assert df_with_samples["user_id"].dtype == "int64"
      assert df_with_samples["item_id"].dtype == "object"
  
      # Check that the negative samples are unique user-item pairs
      assert len(df_with_samples) == len(
          df_with_samples.drop_duplicates(["user_id", "item_id"])
      )
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_negative_sample() without return types