Is filter with $alias set?

@param string $alias
@return boolean
343880
public function has($alias)
    {
        if ($alias instanceof EntityFilterInterface) {
            $alias = $alias->getName();
        }
        return isset($this->filters[$alias]);
    }
936835
protected function resolvePatternAlias($alias)
	{
		if (isset($this->patterns[$alias]) and $class = $this->patterns[$alias]->resolve($alias))
		{
			return $class;
		}

		foreach ($this->patterns as $resolver)
		{
			if ($class = $resolver->resolve($alias))
			{
				return $class;
			}
		}

		return false;
	}
187743
public function findActiveByAlias($alias)
    {
        $query = $this->createValuedQueryBuilder('c')
            ->where('c.alias = :alias')
            ->andWhere('c.active = :active')
            ->setParameters(['alias' => $alias, 'active' => true])
            ->getQuery();

        return $query->useResultCache(true, self::CACHE_TTL)->getSingleResult();
    }
296534
public function getMimeType($alias)
    {
        if (isset($this->_mimeTypes[$alias])) {
            return $this->_mimeTypes[$alias];
        }

        return false;
    }
377919
public function setAlias($alias)
    {
        if (!$this->isValidAlias($alias)) {
            return false;
        }

        $updateAliasStm = $this->connection->prepare("UPDATE Page SET alias = :alias WHERE page_id = :page_id");
        $updateAliasStm->bindParam(":alias", $this->alias);
        $updateAliasStm->bindParam(":page_id", $this->page_id);
        $this->alias = $alias;
        $updateAliasStm->execute();

        return true;
    }
1134258
public function isQueued($alias)
    {
        $query = $this->createQueryBuilder('c')
            ->where('c.alias = :alias')
            ->andWhere('c.ended is NULL')
            ->setParameter('alias', $alias)
            ->getQuery();

        $result = $query->setMaxResults(1)->getOneOrNullResult();

        if ($result)
            return true;

        return false;
    }
891248
private function isJoinUnique($table, $alias)
    {
        foreach ($this->join as $join) {
            if ($join['table'] == $table && $join['alias'] == $alias) {
                return false;
            }
        }

        return true;
    }
562734
public function setAlias($alias)
    {
        /**
         * @T00D00
         */
        $this->alias = $alias;
        $this->getQuery()->alias($alias);

        return $this;
    }
844425
public function hasSubqueryAlias($alias)
    {
        return $this->hasAlias($alias) && $this->getExpression($this->getHash($alias)) instanceof Expr\Subquery;
    }
1361600
protected function aliasAction($alias)
    {
        $request = $this->getRequest();
        $request->setActionName($alias);
        $request->setParam($request->getActionKey(), $alias);
    }
88757
public function getType($alias)
    {
        if (array_key_exists($alias, $this->types)) {
            return $this->types[$alias];
        }

        return false;
    }
240970
public function remove($alias)
    {
        unset(
            $this->_instances[$alias],
            $this->_options[$alias],
            $this->_config[$alias]
        );
    }
573365
public static function hasAlias(string $alias): bool
    {
        // empty OR not an alias
        if (!$alias || $alias[0] !== '@') {
            return false;
        }

        return isset(self::$aliases[$alias]);
    }
282624
private function checkAliasProperty(string &$aliasProperty): bool
    {
        preg_match_all('/\w+/', $aliasProperty, $match);
        $aliasProperty = implode('', $match[0]);

        if (!preg_match('/^([A-z]|_]+)/', $aliasProperty)) {
            $aliasProperty = $this->prefix . $aliasProperty;
        }

        return true;
    }
68472
private function get_alias_property( $alias )
	{
		if ( array_key_exists( $alias, $this->aliases ) )
			return $this->aliases[$alias];

		return $alias;
	}
817850
public function load($alias)
    {
        if (array_key_exists($alias, $this->aliases)) {
            return class_alias($this->aliases[$alias], $alias);
        }

        return false;
    }
1251608
public function get(string $alias = null)
    {
        if (is_null($alias)) {
            return $this->aliases;
        }

        return $this->has($alias) ? $this->aliases[$alias] : false;
    }