long activeTasksCost(final SortedSet<TaskId> activeTasks,
                         final SortedMap<ProcessId, ClientState> clientStates,
                         final int trafficCost,
                         final int nonOverlapCost) {
        return tasksCost(activeTasks, clientStates, trafficCost, nonOverlapCost, ClientState::hasActiveTask, false, false);
    }
Compute the cost for the provided {@code activeTasks}. The passed in active tasks must be contained in {@code clientState}.
streams/src/main/java/org/apache/kafka/streams/processor/internals/assignment/RackAwareTaskAssignor.java