anchor.diff:          |> Seq.map toCommodityPrice
           |> Seq.toList
   
  +    let serializePrices (path : string) (prices : list<CommodityPrice>) =
  +        let toPriceString (price : CommodityPrice) =
  +            // format is "P DATE SYMBOL PRICE"
  +            sprintf "P %s %s %s" (price.Date.ToString("yyyy-MM-dd")) price.Commodity (price.Price.ToString())
  +        use sw = new StreamWriter(path, false)
  +        prices
  +        |> List.iter (fun price -> sw.WriteLine(toPriceString price))
  +        sw.Close()
  +
       let printPrices (prices : list<CommodityPrice>) =
           let printMatch (price : CommodityPrice) =
               do printfn "%s - %s - %s" price.Commodity (price.Date.ToString("yyyy-MM-dd")) (price.Price.ToString())
  
positive.code: 
  
      let path = @"C:\Users\Mark\Nexus\Documents\finances\ledger\tdb900.html"
      let url = "https://www.google.com/finance/historical?q=MUTF_CA%3ATDB900&startdate=Mar+28%2C+2008&enddate=Jun+28%2C+2014&num=60"
      //let url_full = "https://www.google.com/finance/historical?q=NASDAQ%3AGOOGL&startdate=Apr+24%2C+2007&enddate=Jun+17%2C+2014&num=30&start=30"
      
  
negative.code: 
      html
      |> scrapePrices "TDB900"
      |> serializePrices prices_path
      
      html
      |> scrapePagination
  