code: def test_score_function_null(daily_data):
      """Tests fit and its compatibility with predict/score.
      Checks score function accuracy with null model
      """
      model = SilverkiteEstimator(
          null_model_params={"strategy": "mean"},
          fit_algorithm_dict={
              "fit_algorithm_params": {"fit_intercept": False}
          },
      )
      assert model.fit_algorithm_dict == {
          "fit_algorithm_params": {"fit_intercept": False}
      }
      train_df = daily_data["train_df"]
  
      model.fit(
          train_df, time_col=cst.TIME_COL, value_col=cst.VALUE_COL
      )
      assert model.fit_algorithm_dict == {
          "fit_algorithm": "linear",
          "fit_algorithm_params": {"fit_intercept": False},
      }
      score = model.score(
          daily_data["test_df"], daily_data["test_df"][cst.VALUE_COL]
      )
      assert score == pytest.approx(0.90, rel=1e-2)
  
imports: import datetime
  import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
  from sklearn.linear_model import SGDRegressor
  from sklearn.metrics import mean_squared_error
  import greykite.common.constants
  from greykite.algo.forecast.silverkite.forecast_silverkite import SilverkiteForecast
  from greykite.common.features.timeseries_features import convert_date_to_continuous_time
  from greykite.common.features.timeseries_impute import impute_with_lags
  from greykite.common.python_utils import assert_equal
  from greykite.common.testing_utils import daily_data_reg
  from greykite.common.testing_utils import generate_df_for_tests
  from greykite.common.testing_utils import generate_df_with_reg_for_tests
  from greykite.sklearn.estimator.silverkite_estimator import SilverkiteEstimator
  from greykite.sklearn.estimator.testing_utils import params_component_breakdowns
  from greykite.sklearn.estimator.testing_utils import params_components
label_desc: Use image node_id 10 for calling a global function with example usage: test_score_function_null(daily_data) without return types