while IFS='=' read -r key values; do
        read -ra values <<< "$values"

        case $key in
            Requires|OnFailure)
                # only add hard dependencies (not Wants)
                map add_systemd_unit "${values[@]}"
                ;;
            Exec*)
                # do not add binaries unless they are required,
                # strip special executable prefixes
                case ${values[0]} in
                    -*)  ;;
                    !!*) add_binary "${values[0]#!!}" ;;
                    *)   add_binary "${values[0]#[@!:+]}" ;;
                esac
                ;;
        esac

    done <"$unit"