anchor.diff:  
   
       [<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
  
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:         | [<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 =
  