# File lib/mail/parts_list.rb, line 20
    def sort!(order)
      sorted = self.sort do |a, b|
        # OK, 10000 is arbitrary... if anyone actually wants to explicitly sort 10000 parts of a
        # single email message... please show me a use case and I'll put more work into this method,
        # in the meantime, it works :)
        a_order = order.index(a[:content_type].string.downcase) || 10000
        b_order = order.index(b[:content_type].string.downcase) || 10000
        a_order <=> b_order
      end
      self.clear
      sorted.each { |p| self << p }
    end