# File lib/mail/parsers/rfc2822.rb, line 2282
    def _nt_mailbox_list_group
      start_index = index
      if node_cache[:mailbox_list_group].has_key?(index)
        cached = node_cache[:mailbox_list_group][index]
        if cached
          cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
          @index = cached.interval.end
        end
        return cached
      end

      r0 = _nt_mailbox_list
      r0.extend(MailboxListGroup0)

      node_cache[:mailbox_list_group][start_index] = r0

      r0
    end