code: public int getTotalUsedCapacity() {
          int totalCapacity = 0;
          for (Entry<String, ParallelTask> entry : inprogressTaskMap.entrySet()) {
              ParallelTask task = entry.getValue();
              if (task != null)
                  totalCapacity += task.capacityUsed();
  
          }
          return totalCapacity;
      }
docs: get current total used capacity.
  
  @return the total used capacity