src/Reflection/ReflectionClass.php
public function getProperties(?int $filter = null): array
    {
        return (null === $filter) ?
            $this->reflectionClass->getProperties()
            : $this->reflectionClass->getProperties($filter);
    }
public function getProperties(?int $filter = null): array
    {
        return (null === $filter) ?
            $this->reflectionClass->getProperties()
            : $this->reflectionClass->getProperties($filter);
    }
@param int|null $filter

@return array|\ReflectionProperty[]