public void block (void* instance, ulong handler_id)
Blocks a handler of an instance so it will not be called during any signal emissions unless it is unblocked again.
Thus "blocking" a signal handler means to temporarily deactivate it, a signal handler has to be unblocked exactly the same amount of times it has been blocked before to become active again.
handler_id has to be a valid signal handler id, connected to a signal of
The instance to block the signal handler of.
Handler id of the handler to be blocked.