Messenger::getPrivateChat

public function getPrivateChat(int $fromUserId, int $toUserId): Chat
{
	$chatFactory = ChatFactory::getInstance();
	$chat = $chatFactory
		->setContext($this->context)
		->getPrivateChat($fromUserId, $toUserId)
	;

	if (!$chat)
	{
		return new NullChat();
	}

	return $chat;
}