I was recently playing on Mineverse, a Minecraft server. I was playing prison, and I was enchanting a diamond sword. I put on 30 levels of XP, and guess what came out...
Unbreaking III, Sharpness IV, Knockback II, and Fire Aspect II, together.
Is this possible in vanilla? I've been reading up on enchantment mechanics, and it seems to be impossible (4 enchantments in one try). The levels are also maxed out, making me think that this may have been something special on the server. However, most of my previous enchantments seemed normal.