docs: public void endOperation() {
          if (this.opCounter.decrementAndGet() == 0) {
              // means the engine is idle, so, set the timestamp
              this.lastIdleTimestamp.set(this.timerService.getCurrentTime());
              if (this.endOperationListener != null) {
                  this.endOperationListener.endOperation(this.getKnowledgeRuntime());
              }
          }
      }