Weak hands cannot be planted, meager skills have no foundation. Shallow wisdom is futile, how can one hope for a good name?扰扰从役倦，屑屑身事微。少壮轻年月，迟暮惜光辉。
cache[$key] = $value;
}
/**
* Gets a value from the cache.
*
* @param string $key The cache key.
*
* @return mixed|null The cached value or null if not set.
*/
public function getCache($key, $default = null)
{
return $this->isCacheSet($key) ? $this->cache[$key] : $default;
}
/**
* Checks if a cache key is set.
*
* @param string $key The cache key.
*
* @return bool True if the cache key is set, false otherwise.
*/
public function isCacheSet($key)
{
return isset($this->cache[$key]);