/**
* Creates a Problem.
* @param $type Problem type: 'text', 'equation', ... ?
* @param $content An xml string with the problem content. The format depends on the $type.
*/
public static function create($type, $content)
{
if ($type == 'text') {
return ProblemFactory::createText($content);
}
throw new Exception("Problem type {$type} is undefined.");
}