src/Router.php
public function log($message, ...$args)
    {
        if ($this->logger) {
            $args[] = $this->stopwatch ? microtime(true) - $this->stopwatch : 0;
            $this->logger->debug(sprintf($message . ' (%.2fs)', ...$args));
        }
        return $this;
    }
public function log($message, ...$args)
    {
        if ($this->logger) {
            $args[] = $this->stopwatch ? microtime(true) - $this->stopwatch : 0;
            $this->logger->debug(sprintf($message . ' (%.2fs)', ...$args));
        }
        return $this;
    }
Log a debug message, and append time elapsed since ->run() was called

@param string $message sprintf compatible string
@param mixed[] $args Data to pass to sprintf
@return self