anchor.diff:              [x] Fetch page and extract prices
               [x] Generate next URL
   
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   *)
   
   module Main =
  
positive.code: 
      type CommodityConfig = {
          Commodity: Commodity;
          GoogleFinanceKey: string;
      }
  
      type CommodityPrice = {
  
negative.code:             match usage.ZeroBalanceDate, cpDB.LastDate with
              | None, lastDate when lastDate < System.DateTime.Today ->
                  let startDate = lastDate.AddDays(1.0)
                  let baseURL = generateBaseURL config.GoogleFinanceSearchSymbol startDate (Some System.DateTime.Today)
                  getPrices baseURL 0 usage.Commodity
              | Some zeroBalanceDate, lastDate when lastDate < zeroBalanceDate ->
                  let startDate = lastDate.AddDays(1.0)
                  let baseURL = generateBaseURL config.GoogleFinanceSearchSymbol startDate (Some zeroBalanceDate)
                  getPrices baseURL 0 usage.Commodity
              | otherwise -> List.Empty
  
  