Multiple occurrences does not seem to be handled properly

[rgiot]

Hello,

I have an argument defined this way

                  .arg(
                      Arg::new("INCLUDE_DIRECTORIES")
                          .help("Provide additional directories used to search files.")
                          .long("include")
                          .short('I')
                          .takes_value(true)
                          .multiple_occurrences(true)
                          .number_of_values(1)
                          .value_hint(ValueHint::DirPath)
                  )

Klask properly generates the interface that propose to select several directories.

However, it probably does not generate the arguments properly as an "internal match error" using the additional INCLUDE_DIRECTORIES is raised.

I can provide more details or do some specific tests if needed