anchor.diff:          | Filter _ -> "Filter the list of tests by a hierarchy that's slash (/) separated."
           | Filter_Test_List _ -> "Filter the list of test lists by a substring."
           | Filter_Test_Case _ -> "Filter the list of test cases by a substring."
  +        | Run _ -> "Run only provided tests"
           | List_Tests -> "Doesn't run tests, print out list of tests instead"
   
     [<CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
  
positive.code:     | Filter of hiera:string
      | Filter_Test_List of substring:string
      | Filter_Test_Case of substring:string
      | List_Tests
  
      interface IArgParserTemplate with
  
negative.code:         | Filter hiera -> fun o -> {o with filter = Test.filter (fun s -> s.StartsWith hiera )}
          | Filter_Test_List name ->  fun o -> {o with filter = Test.filter (fun s -> s |> getTestList |> Array.exists(fun s -> s.Contains name )) }
          | Filter_Test_Case name ->  fun o -> {o with filter = Test.filter (fun s -> s |> getTastCase |> fun s -> s.Contains name )}
          | Run tests -> fun o -> {o with filter = Test.filter (fun s -> tests |> List.exists ((=) s) )}
          | List_Tests -> id
  
  
  