Sticky pistons can pull a block 1 tick after pushing one

1 Connect the piston taken out of the pulsar signal using the observer block
2 Back and forth while the pressure-sensitive adhesive piston with a block

This is not might be a specification but is inconvenient and can not use a piston type t flip-flop！

Edit by PHO:
Sticky pistons received a 1-tick on-pulse should push a block but shouldn't pull it back. Since an observer block emits a 1-tick pulse, it should be able to cause this phenomenon. However in 0.15.0 beta build 1, sticky pistons do pull a block even when it pushed a block 1 tick before that.