Value-of-contango-of-the-VIX-term-structure

CODE:
using WealthLab.Backtest;
using System;
using WealthLab.Core;
using WealthLab.Indicators;
using System.Collections.Generic;

namespace WealthScript1 
{
    public class ContangoSample : UserStrategyBase
    {
        //create indicators and other objects here, this is executed prior to the main trading loop
        public override void Initialize(BarHistory bars)
        {
         BarHistory Ubars = GetHistory(bars, "VIXU22");
         BarHistory Zbars = GetHistory(bars, "VIXZ22");
         _contango = Zbars.Close - Ubars.Close;

         PlotTimeSeriesLine(_contango, "Contango", "CPane");
        }

        //execute the strategy rules here, this is executed once for each bar in the backtest history
        public override void Execute(BarHistory bars, int idx)
        {            
        }

      //declare private variables below
      TimeSeries _contango; 
    }
}