Stub::convert

public function convert($instance)
{
	$result = new Result();

	if(Item::isA($instance))
	{
		$instance = clone $instance;
		$instance->setId(0);

		// mark that $instance as a "brand new"
		$cached = $instance->getCachedFields();
		foreach($cached as $field)
		{
			$instance->setFieldModified($field);
		}

		$result->setInstance($instance);
	}
	elseif(Collection::isA($instance))
	{
		$result->setInstance($instance);
	}
	else
	{
		$result->addError('ILLEGAL_SOURCE_INSTANCE', 'Illegal source instance');
	}

	return $result;
}