code: def test_bts_simulation_dt(self):
      code = """
  def initialize(context):
      pass
  """
      algo = self.make_algo(script=code, metrics=metrics.load("none"))
      algo.metrics_tracker = algo._create_metrics_tracker()
      benchmark_source = algo._create_benchmark_source()
      algo.metrics_tracker.handle_start_of_simulation(benchmark_source)
  
      dt = pd.Timestamp("2016-08-04 9:13:14", tz="US/Eastern")
      algo_simulator = AlgorithmSimulator(
          algo,
          self.sim_params,
          self.data_portal,
          BeforeTradingStartsOnlyClock(dt),
          benchmark_source,
          NoRestrictions(),
          None,
      )
  
      # run through the algo's simulation
      list(algo_simulator.transform())
  
      # since the clock only ever emitted a single before_trading_start
      # event, we can check that the simulation_dt was properly set
      self.assertEqual(dt, algo_simulator.simulation_dt)
  
imports: import pandas
  from zipline.gens.sim_engine import BEFORE_TRADING_START_BAR
  from zipline.finance.asset_restrictions import NoRestrictions
  from zipline.finance import metrics
  from zipline.finance.trading import SimulationParameters
  from zipline.gens.tradesimulation import AlgorithmSimulator
  from zipline.testing.core import parameter_space
  import zipline.testing.fixtures
label_desc: Use image node_id 1 for calling the TestBeforeTradingStartSimulationDt obj's underlying member method code with example usage: obj.test_bts_simulation_dt() without return types