Rubyのprivateは思ったよりもprivateじゃない件

private_test.rb

module Piyo
    private

    def piyo_inner
        puts "piyo"
    end
end

class Hoge
    def hoge
        hoge_inner
    end

    private

    def hoge_inner
        puts "hoge"
    end

end

class HogeHoge < Hoge
    include Piyo

    def hogehoge
        hoge_inner
        piyo_inner
    end
end

HogeHoge.new.hogehoge