code: private void addCommandPolling(final CommandImpl command) throws DevFailed {
          if (MANAGER == null) {
              startCache();
          }
          removeCommandPolling(command);
          final CommandCache cache = new CommandCache(MANAGER, command, deviceName, deviceLock, aroundInvoke);
          if (command.getPollingPeriod() == 0) {
              extTrigCommandCacheMap.put(command, cache);
          } else {
              commandCacheMap.put(command, cache);
          }
          updatePoolConf();
      }
docs: Add command as polled
  
  @param command
  @throws DevFailed