Answer true if an attribute exists for the authenticated user.

@param string $key attribute name

@return bool
@warning should only be called after phpCAS::forceAuthentication()
or phpCAS::checkAuthentication().
504283
public static function hasAttribute($key)
    {
        phpCAS::_validateClientExists();

        try {
            return self::$_PHPCAS_CLIENT->hasAttribute($key);
        } catch (Exception $e) {
            phpCAS :: error(get_class($e) . ': ' . $e->getMessage());
        }
    }
566699
public function hasKey(string $key): bool
    {
        return $key && strpos($key, '@@') === false && file_exists($this->getPathFromKey($key));
    }
88651
public function exists($key)
	{
		if(empty($this->meta)) return false;
		return array_key_exists($key, $this->meta);
	}
669642
public function exists(string $key): bool
    {
        $key = $this->getKey($key);

        return cache()->has($key);
    }
1314065
public function isExist($key = null)
	{
		return $key = is_null($key) ? false : ($this->find($key) ? true : false);
	}
994593
public function __isset($key)
    {
        return (isset($this->attributes[$key]) && null !== $this->getAttributeValue($key));
    }
1119273
public function __isset($key)
    {
        if (isset($this->custom_attributes[$key]))
            return true;

        return ! is_null($this->getAttribute($key));
    }
1068984
public function existsItem(string $key): bool
    {
        if (!$this->adapter instanceof iAdapter) {
            return false;
        }

        $storeKey = $this->calculateStoreKey($key);

        // check static-cache
        if ($this->checkForStaticCache($storeKey)) {
            return true;
        }

        return $this->adapter->exists($storeKey);
    }
683882
public function has(string $key): bool
    {
        $sql =  'SELECT COUNT(*) AS Cnt FROM #__' . $this->table
                . " WHERE `" . $this->keyField . "`='" . $this->db->addEscape($key) . "'";
        $cnt = $this->db->getValue($sql, 'Cnt');
        if (null === $cnt) {
            return false;
        }
        return 0 < (int) $cnt;
    }
278793
public function has($key)
	{
		$key = $this->id($key);
		return $this->apcu ? apcu_exists($key) : apc_exists($key);
	}
288391
public function has(string $key){
        $data   = $this->status() === self::ACTIVE
            ? $_SESSION : $this->finishedData;
        
        return array_key_exists($key, $data);
    }
21708
public function hasConfig(string $key)
    {
        $redis = $this->getDI()->getRedis();
        $hashKey = $this->getNotificationKey(); //'user_notifications_'.$this->user_id;

        return $redis->hGet($hashKey, $key);
    }
63764
public function get($key)
    {
        if (!isset($this->attributes[$key])) {
            return false;
        }

        return $this->attributes[$key];
    }
204401
protected function isAllowedKey($key): bool
    {
        return empty($this->allowedKeys) || \in_array($key, $this->allowedKeys, true);
    }
884792
public function hasMapping($key)
    {
        if (is_null($this->mappedAttributes)) {
            $this->parseMappings();
        }

        return array_key_exists((string) $key, $this->mappedAttributes);
    }
382943
private function hasAccess($key): bool
    {
        $hasAccess = $this->getServiceLocator()->get('MelisCoreRights')->canAccess($key);

        return $hasAccess;
    }
159473
protected function isNativeAttribute($key)
    {
        if($this->timestamps && in_array($key, ['updated_at', 'created_at'])){

            return true;

        } elseif($key == $this->primaryKey){

            return true;

        }

        return false;
    }