private void ensureArraySize() {
        if (events.length == length) {
            final Event[] tmp = new Event[events.length * 2];
            System.arraycopy(events, 0, tmp, 0, events.length);
            events = tmp;
        }
    }
Make sure the event array is going to be big enough to hold the item that
is just about to be added.
stroom-pipeline/src/main/java/stroom/pipeline/filter/SplitFilter.java