protected final AtomicInteger initRunningFilterIndex(I zuulMesg) {
        AtomicInteger idx = new AtomicInteger(0);
        zuulMesg.getContext().put(RUNNING_FILTER_IDX_SESSION_CTX_KEY, idx);
        return idx;
    }
Subclasses of this class are supposed to be thread safe

Created by saroskar on 5/18/17.
zuul-core/src/main/java/com/netflix/zuul/netty/filter/BaseZuulFilterRunner.java