code: public synchronized void startCommandPolling(final CommandImpl command) throws DevFailed {
          addCommandPolling(command);
          LOGGER.debug("starting command {} for polling on device {}", command.getName(), deviceName);
          if (command.getPollingPeriod() != 0) {
              commandCacheMap.get(command).startRefresh(POLLING_POOL);
          }
      }
docs: Start command polling
  
  @param command
  The command to poll
  @throws DevFailed