Pistons can have two heads at a time and can retain one of its heads

With perfect cps (clicks per second), pistons can have two heads at a time. Breaking a piston retains one of its heads and placing a piston fixes it. The head cannot be broken.

Steps to reproduce:

1. Place a redstone power source
2. Place two pistons with perfect timing
3. Break the original piston
4. Notice the second head is still intact