I’m running a data acquisition and saving all my events as a Tree. Sometimes I get “bad” events which have to be thrown away. I can only check if there were bad events every few seconds. So every few seconds I know that my N previous events (which were accumulated since the last check) are either good or bad. I want to either discard them or save, possibly fast (without copying the whole Tree to another one or so). How to do it with a Tree?