# File lib/mail/parsers/rfc2822.rb, line 108
    def _nt_CR
      start_index = index
      if node_cache[:CR].has_key?(index)
        cached = node_cache[:CR][index]
        if cached
          cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
          @index = cached.interval.end
        end
        return cached
      end

      if has_terminal?("\r", false, index)
        r0 = instantiate_node(SyntaxNode,input, index...(index + 1))
        @index += 1
      else
        terminal_parse_failure("\r")
        r0 = nil
      end

      node_cache[:CR][start_index] = r0

      r0
    end