anchor.diff:  let shipData =
     ParaValue.Parse ships
     |> collect "ship"
  +  |> asArray
     |> Array.filter (tryFind "patrol" >> Option.isSome)
     |> Array.map (fun x -> x?name |> asString)
   printfn "%A" armyData
  
positive.code: let armyData =
    ParaValue.Parse army
    |> collect "army"
    |> Array.map (fun x ->
      let units = x |> collect "unit" |> Array.map (fun u -> u?name |> asString)
      x?name |> asString, units)
  printfn "%A" armyData
  
  
negative.code: let required, optional =
    ParaValue.Parse nodes
    |> collect "node"
    |> asArray
    |> findOptional
  
  required |> Seq.iter (printfn "%s")
  