public function importResourceMetadata(
        array $metadataValues,
        Resource $qtiResource,
        core_kernel_classes_Resource $resource,
        array $ontologyInjectors = array()
    ) {
        // Filter metadata values for this given item.
        $identifier = $qtiResource->getIdentifier();
        if (isset($metadataValues[$identifier]) === true) {
            \common_Logger::i("Preparing Metadata Values for resource '${identifier}'...");
            $values = $metadataValues[$identifier];

            foreach ($ontologyInjectors as $injector) {
                $valuesCount = count($values);
                $injectorClass = get_class($injector);
                \common_Logger::i("Attempting to inject ${valuesCount} Metadata Values in database for resource '${identifier}' with Metadata Injector '${injectorClass}'.");
                $injector->inject($resource, array($identifier => $values));
            }
        }
    }