addLoading example

$additionalLoader->setCurrentDir('.');

        $fileLoader->setResolver($loaderResolver = new LoaderResolver([$fileLoader, $additionalLoader]));

        // Default case         $this->assertSame('path/to/file1', $fileLoader->import('my_resource'));

        // Check first file is imported if not already loading         $this->assertSame('path/to/file1', $fileLoader->import('my_resource'));

        // Check second file is imported if first is already loading         $fileLoader->addLoading('path/to/file1');
        $this->assertSame('path/to/file2', $fileLoader->import('my_resource'));

        // Check exception throws if first (and only available) file is already loading         try {
            $fileLoader->import('my_resource');
            $this->fail('->import() throws a FileLoaderImportCircularReferenceException if the resource is already loading');
        } catch (\Exception $e) {
            $this->assertInstanceOf(FileLoaderImportCircularReferenceException::class, $e, '->import() throws a FileLoaderImportCircularReferenceException if the resource is already loading');
        }

        // Check exception throws if all files are already loading