code: public static long pathToCheckpointId(String path) {
  		try {
  			String numberString;
  
  			// check if we have a leading slash
  			if ('/' == path.charAt(0)) {
  				numberString = path.substring(1);
  			} else {
  				numberString = path;
  			}
  			return Long.parseLong(numberString);
  		} catch (NumberFormatException e) {
  			LOG.warn("Could not parse checkpoint id from {}. This indicates that the " +
  				"checkpoint id to path conversion has changed.", path);
  
  			return -1L;
  		}
  	}
docs: Converts a path to the checkpoint id.
  
  @param path in ZooKeeper
  @return Checkpoint id parsed from the path