public function getPropertyNames()
    {
        $result = array();
        foreach ($this->getLegends() as $legend) {
            $result = array_merge($result, $legend['properties']);
        }

        return $result;
    }
public function getPropertyNames()
    {
        $result = array();
        foreach ($this->getLegends() as $legend) {
            $result = array_merge($result, $legend['properties']);
        }

        return $result;
    }
{@inheritDoc}