code: def exec_train_and_forecast(self, mock_handler, model_name, using):
      # create predictor
      create_sql = f"""
                      CREATE PREDICTOR mindsdb.{model_name}_forecaster
                      FROM pg
                      (select t, H1 from m4 where train = 1) 
                      PREDICT H1
                      USING engine='merlion'{using}
                  """
      ret = self.run_mindsdb_sql(sql=create_sql)
      assert ret.error_code is None, "train failed: " + model_name
  
      self.wait_training(model_name=f"{model_name}_forecaster")
  
      predict_sql = f"""
                      select p.t, p.H1 real, t.H1, t.H1__upper, t.H1__lower
                      from mindsdb.{model_name}_forecaster t
                      inner join pg.m4 p on t.t = p.t
                      where p.train = 0
                  """
      ret = self.run_mindsdb_sql(sql=predict_sql)
      assert ret.error_code is None, "forecast failed: " + model_name
  
imports: import os
  import time
  from unittest.mock import patch
  import pandas
  from mindsdb_sql import parse_sql
  from mindsdb.integrations.handlers.merlion_handler.adapters import DefaultForecasterAdapter, SarimaForecasterAdapter, ProphetForecasterAdapter, MSESForecasterAdapter, IsolationForestDetectorAdapter, WindStatsDetectorAdapter, ProphetDetectorAdapter
  from .executor_test_base import BaseExecutorTest
  import pandas
label_desc: Use image node_id 7 for calling the TestMerlion obj's underlying member method code with example usage: obj.exec_train_and_forecast(mock_handler, model_name, using) without return types