code: protected static Path getCheckpointDirectoryForJob(Path baseCheckpointPath, JobID jobId) {
  		return new Path(baseCheckpointPath, jobId.toString());
  	}
docs: Builds directory into which a specific job checkpoints, meaning the directory inside which
  it creates the checkpoint-specific subdirectories.
  
  <p>This method only succeeds if a base checkpoint directory has been set; otherwise
  the method fails with an exception.
  
  @param jobId The ID of the job
  @return The job's checkpoint directory, re
  
  @throws UnsupportedOperationException Thrown, if no base checkpoint directory has been set.