code: def test_prophet_fit_kwargs_are_passed_down(fit_kwargs: dict):
      """Test that the `fit_kwargs` hyperparameter is passed down to Prophet.fit()."""
      from sktime.datasets import load_airline
      from sktime.forecasting.fbprophet import Prophet
  
      y = load_airline()
      with mock.patch("prophet.forecaster.Prophet.fit") as mock_fit:
          forecaster = Prophet(fit_kwargs=fit_kwargs)
          forecaster.fit(y)
          mock_fit.assert_called_once()
          assert mock_fit.call_args.args == ()
          call_kwargs = mock_fit.call_args.kwargs
          # `df` should always be one of the arguments but
          # we don't care about its actual value here
          call_kwargs.pop("df")
          assert call_kwargs == (fit_kwargs or {})
  
imports: from unittest import mock
  import pandas
  import pytest
  from sktime.forecasting.fbprophet import Prophet
  from sktime.tests.test_switch import run_test_for_class
label_desc: Use image node_id 3 for calling a global function with example usage: test_prophet_fit_kwargs_are_passed_down(fit_kwargs) without return types