code: private void resetDrillDownableCache(String entityId) {
      	try {
      		// has no chart id in settings
      		if (entityId == null) {
      			return;
      		}
      		Entity entity = storageService.getEntityById(entityId);
      		if (entity instanceof Chart) {
      			if (((Chart)entity).isDrillDownable()) {
      				resetCache(entityId);
      			}
      		}
      	} catch  (NotFoundException ex) {
      		LOG.error("Reset cache - not found", ex);
      	}
      }
docs: for drill down reports there is no need to reset cache when we move the widget