protected function doMatch($actual)
    {
        if ($this->isCountable($actual)) {
            $this->count = count($actual);
        }

        if (is_string($actual)) {
            $this->count = strlen($actual);
        }

        if (isset($this->count)) {
            return $this->expected === $this->count;
        }

        throw new InvalidArgumentException('Length matcher requires a string, array, or Countable');
    }