private function buildCacheData()
    {
        $metadata = $this->driver->getMetadataForUser();

        return serialize(
            array_map(function (\ReflectionProperty $property) {
                return $property->getName();
            }, $metadata)
        );
    }
private function buildCacheData()
    {
        $metadata = $this->driver->getMetadataForUser();

        return serialize(
            array_map(function (\ReflectionProperty $property) {
                return $property->getName();
            }, $metadata)
        );
    }
private function buildCacheData ( ) { $ metadata = $ this -> driver -> getMetadataForUser ( ) ; return serialize ( array_map ( function ( \ ReflectionProperty $ property ) { return $ property -> getName ( ) ; } , $ metadata ) ) ; }
Builds the cache data.

@return string
Builds the cache data .