# File lib/mail/parsers/rfc2822.rb, line 4820
    def _nt_msg_id_dot_atom_text
      start_index = index
      if node_cache[:msg_id_dot_atom_text].has_key?(index)
        cached = node_cache[:msg_id_dot_atom_text][index]
        if cached
          cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
          @index = cached.interval.end
        end
        return cached
      end

      s0, i0 = [], index
      loop do
        i1, s1 = index, []
        r2 = _nt_msg_id_domain_text
        s1 << r2
        if r2
          if has_terminal?(".", false, index)
            r4 = instantiate_node(SyntaxNode,input, index...(index + 1))
            @index += 1
          else
            terminal_parse_failure(".")
            r4 = nil
          end
          if r4
            r3 = r4
          else
            r3 = instantiate_node(SyntaxNode,input, index...index)
          end
          s1 << r3
        end
        if s1.last
          r1 = instantiate_node(SyntaxNode,input, i1...index, s1)
          r1.extend(MsgIdDotAtomText0)
        else
          @index = i1
          r1 = nil
        end
        if r1
          s0 << r1
        else
          break
        end
      end
      if s0.empty?
        @index = i0
        r0 = nil
      else
        r0 = instantiate_node(SyntaxNode,input, i0...index, s0)
      end

      node_cache[:msg_id_dot_atom_text][start_index] = r0

      r0
    end