public function testOpenBlockExtension()
{
$count = 0;
$parser = new SSTemplateParser();
$parser->addOpenBlock('test', function ($res) use(&$count) {
$count++;
});
$template = new SSViewer_FromString("<% test %>", $parser);
$template->process(new SSViewerTestFixture());
$this->assertEquals(1, $count);
}