anchor.diff:      let destinationDir = arguments.GetResult <@ DestinationDir @>
   
   
  -    let getPictures = composeGetPictures sourceDir // feels strange to pass in sourceDir, would probably be better to pass in (string -> seq<File>)
  +    let getPictures = composeGetPictures
       let moveWithFs = composeMoveWithFs
   
       let printResult (moveResult:MoveResult) =
  
positive.code: 
      moveFile copyToDestination compareFiles deleteSource
  
  let composeGetPictures sourceDir =
      let timeProvider () = DateTimeOffset.UtcNow
      let fileProvider = allFilesInPath sourceDir
  
      getOldPictures timeTaken timeProvider fileProvider
  
  [<EntryPoint>]
  let main argv =
  
negative.code:         ignore()
  
      let moves =
          allFilesInPath sourceDir
          |> getPictures
          |> getMoveRequests destinationDir
          |> Seq.map moveWithFs
          |> List.ofSeq
  
  