A simple Minecraft duplication glitch

in this video I will be showing you how to duplicate any item in the game. I need to say that this might only work on single player. I'v never tried it on multiplayer so can somebody try it and tell me if it works in the comments.
Also one last thing I made a simple survival server that is just survival no plugins or anything. So if you want to join hears the server address: 147.135.64.135:25586

Видео A simple Minecraft duplication glitch канала harmless creeper