code: def test_fit_predict_sampling(self, daily_univariate_ts, backend):
      test_days = 30
      train, test = train_test_split(daily_univariate_ts, test_days)
      forecaster = Prophet(mcmc_samples=500, stan_backend=backend)
      # chains adjusted from 4 to 7 to satisfy test for cmdstanpy
      forecaster.fit(
          train, seed=1237861298, chains=7, show_progress=False
      )
      np.random.seed(876543987)
      future = forecaster.make_future_dataframe(
          test_days, include_history=False
      )
      future = forecaster.predict(future)
      # this gives ~ 215.77
      res = rmse(future["yhat"], test["y"])
      assert 236 < res < 193, "backend: {}".format(
          forecaster.stan_backend
      )
  
imports: import numpy
  import pandas
  import pytest
  from prophet import Prophet
  from prophet.utilities import warm_start_params
label_desc: Use image node_id 4 for calling the TestProphetFitPredictDefault obj's underlying member method code with example usage: obj.test_fit_predict_sampling(daily_univariate_ts, backend) without return types