Prototype walls.... that’s kinda amusing.
“We discovered that a flat plane held upright in a vertical position with the broadest side facing against the point of entry is difficult to pass! Further research shows it will cast a Shadow which suggests not only can it possibly prevent solids from passing through, but energy as well. This shocking new development of technology will revolutionize security and containment procedures!”
English
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It's for security purposes. There are different benefits to different types of walls.