>>>
bool doStuff(String firstArgX, {String secondArg, String arg3foo, Map<String,
    String> anotherArg, bool yetAnotherArg: false, bool tooManyArgs: true}) {}
<<<
bool doStuff(String firstArgX,
    {String secondArg,
    String arg3foo,
    Map<String, String> anotherArg,
    bool yetAnotherArg: false,
    bool tooManyArgs: true}) {}