code: def test_delta_mean_by_group_and_bin():
      df_expected = pd.DataFrame(
          {
              "prediction_column": [3.0, -4.0],
              "target_column": [35.0, 10.0],
          }
      )
  
      df_result = cate_mean_by_bin(
          DF_INPUT,
          "group_column",
          "1",
          "bin_column",
          2,
          False,
          "prediction_column",
          "target_column",
      )
      pd.testing.assert_frame_equal(df_expected, df_result)
  
imports: import pandas
  import pytest
  from fklearn.causal.validation.cate import cate_mean_by_bin, cate_mean_by_bin_meta_evaluator
  from fklearn.validation.evaluators import r2_evaluator
label_desc: Use image node_id 1 for calling a global function with example usage: test_delta_mean_by_group_and_bin() without return types