code: public static Tag status(ServerWebExchange exchange) {
  		HttpStatus status = exchange.getResponse().getStatusCode();
  		if (status == null) {
  			status = HttpStatus.OK;
  		}
  		return Tag.of("status", String.valueOf(status.value()));
  	}
docs: Creates a {@code status} tag based on the response status of the given
  {@code exchange}.
  @param exchange the exchange
  @return the status tag derived from the response status