anchor.diff:          | [<CustomAppSettings "Foo">] CustomAppConfig of string * int
           | [<EqualsAssignment>] Assignment of string
           | [<First>] First_Parameter of string
  +        | [<CliPrefix(CliPrefix.Dash)>] A
  +        | [<CliPrefix(CliPrefix.Dash)>] B
  +        | [<CliPrefix(CliPrefix.Dash)>] C
       with
           interface IArgParserTemplate with
               member a.Usage =
  
positive.code:                 | Assignment _ -> "assign with equals operation."
                  | CustomAppConfig _ -> "parameter with custom AppConfig key."
                  | First_Parameter _ -> "parameter that has to appear at beginning of command line args."
  
      let parser = ArgumentParser.Create<Argument> "usage string"
  
  
negative.code: 
  
      [<Fact>]
      let ``Should recognize grouped switches`` () =
          let args = [| "-cba"; "-cc" |]
          let results = parser.ParseCommandLine(args, ignoreMissing = true)
          results.GetAllResults() |> should equal [C; B; A; C; C]
  
  
      [<Fact>]
      let ``Should allow '--help' before first args`` () =
          let result = parser.Parse([| "--help" ; "--first-parameter" ; "bar"|], raiseOnUsage = false, ignoreMissing = true)
          result.IsUsageRequested |> should equal true
  