void release(boolean success, RequestDuration searchTime) {
            allocations--;
            if (allocations < 0) {
                log.warning("Double free of query target group detected");
                allocations = 0;
            }
            if (success) {
                decayer.decay(searchTime);
            }
        }
Release an allocation given by {@link #takeGroup}. The release must be done exactly once for each allocation.

@param group previously allocated group
@param success was the query successful
@param searchTime query execution time, used for adaptive load balancing
container-search/src/main/java/com/yahoo/search/dispatch/LoadBalancer.java