Now it happened what I was afraid of. I was trying to look for a particular chinese restaurant that should have vegan food, but cause was not able to find it, chose another place thinking I can easily avoid such things as milk, eggs and oyster sauce. I asked whether they have vegan food and after green light was given, I happily ordered a portion. In the middle of eating I realised that it's containing fried egg with vegetables. I was so angry to myself to not ask more carefully what the food is actually containing, I should have also realised that noodles most likely also contain eggs. But this was important lesson: vegan has to be always paranoid in order to avoid animal products. Because of that it would be quite troublesome to travel in countries where you don't know the local language.