public static function fromJson($config, Form_Elements_FieldsetModel $form=null)
	{
		$contextProfile = AgaviConfig::get('core.default_context');
		if(is_null($contextProfile))
		{
			$contextProfile = md5(microtime());
			AgaviConfig::set('core.default_context', $contextProfile);
		}
		$context = AgaviContext::getInstance();
		$_form = $context->getModel('Form', 'Form', array($config, $form));
		self::parseChildren($config, $_form);
		return $_form;
	}