code: def classic_metrics():
      metrics = default_metrics()
      metrics.add(_ClassicRiskMetrics())
      return metrics
  
imports: import empyrical
  from zipline.utils.deprecate import deprecated
  from .core import metrics_sets, register, unregister, load
  from .metric import AlphaBeta, BenchmarkReturnsAndVolatility, CashFlow, DailyLedgerField, MaxLeverage, NumTradingDays, Orders, PeriodLabel, PNL, Returns, ReturnsStatistic, SimpleLedgerField, StartOfPeriodLedgerField, Transactions, _ConstantCumulativeRiskMetric, _ClassicRiskMetrics
  from .tracker import MetricsTracker
label_desc: Use image node_id 2 for calling a global function with example usage: classic_metrics() and returns: metrics