public function testEnableWithCustomClasses()
 {
     FulltextSearchable::enable(array('SilverStripe\\Assets\\File'));
     $this->assertTrue(File::has_extension('SilverStripe\\ORM\\Search\\FulltextSearchable'));
     File::remove_extension('SilverStripe\\ORM\\Search\\FulltextSearchable');
     $this->assertFalse(File::has_extension('SilverStripe\\ORM\\Search\\FulltextSearchable'));
 }