forcefield.png in misc folder (1.8, textures) what is it for?

Question

Once I saw on server forcefield-like animated wall. It looks like this:

https://www.youtube.com/watch?v=RfoIUX5YEXA

I want to find plugin or whatever that animated wall was made of. It is plugins based server (so no mods and additional textures). I've opened minecraft resources and in \versions\1.8.8.jar\assets\minecraft\textures\misc I've found forcefield.png. But I've never seen it being used in vanilla minecraft. So is it some special block or I should look for plugin?

Answer 1

bnnjxdkdijpisjjjjjjjffffffffffffffffffffffffffffffffffffffpddddddddddddddddddddddddd

Answer 2

It's the worldborder you can set it with commands ( /worldborder )