--- caller([level])

    level ʾ(άϡ1)θƤӽФξ $@
    ηΥХåȥ졼(ʸ)Ȥ֤ޤȥåץ٥
    ϶֤ޤcaller ͤ $@ 뤳Ȥ
    㳰ȯ֤ǤޤʲΤ褦ʥɤ caller ƤӽФ
    Υåȥ졼ɽǤޤ

        puts caller(0)

