Error in segment tree beats implementation

[peltorator]

Here you add g to lazy_add and lazy_update. But here you first apply update and then add. So you'll add g twice. I think you just need to delete lines 171-173

[kmyk]

It seems correct with the current implementation because:

1. in the pushdown method, it returns from the method and doesn't add after applying update, and
2. deleting lines 171-173 makes the tests using DSL_2_G and DSL_2_H fail.

However, anyway, thank you for telling me a possible bug!