Redstone Block Only 5x5 Seamless Door

RedstonerBuilding → Redstone Block Only 5x5 Seamless Door

CHALLENGE

A year ago VoodooCraft made a 5x5 seamless door using no repeaters or torches. But I challenge you to make one using nothing but the following.

Piston Sticky Piston Redstone Block Any Generic Minecraft Block Any Immovable Block

I might try it if i have time