With the previous commit, the transform application is skipped when the state is already changed. But it turns out the previous commit breaks slider animation in the standard editor. This is probably due to the transforms are applied before nested hit objects are added.
It is more convenient than using the constructor because the only limited kind of expression is allowed in a base constructor call.
Also, the object initializer syntax can be used.
Hidden properties are used when the type is the base class. It caused issues when `DrawableHitObject` logic is factored out to `PoolableDrawableWithLifetime` because it is using the base `LifetimeEntry`, not `HitObjectLifetimeEntry`.
It was added in c9f38f7bb6, which
specified 2021 in another place (and was committed in October of 2020
anyway). Update the year so that it doesn't get culled prematurely.