protected function getMappingClasses(): array
    {
        AnnotationRegistry::registerLoader('class_exists');

        $mappingClasses = [];

        foreach ($this->locator->getMappingFiles() as $annotationFile) {
            $mappingClasses[] = $this->loadClassFromFile($annotationFile);
        }

        return \array_map(
            function (string $sourceClass) {
                return new \ReflectionClass($sourceClass);
            },
            \array_filter(\array_unique($mappingClasses))
        );
    }