code: public ImageVectorizationResult getImageVectorizationResult() throws Exception {
  		Future<ImageVectorizationResult> future = pool.poll();
  		if (future == null) {
  			return null;
  		} else {
  			try {
  				ImageVectorizationResult imvr = future.get();
  				return imvr;
  			} catch (Exception e) {
  				throw e;
  			} finally {
  				// in any case (Exception or not) the numPendingTask should be reduced
  				numPendingTasks--;
  			}
  		}
  	}
docs: Takes and returns a vectorization result from the pool.
  
  @return the vectorization result, or null in no results are ready
  @throws Exception
  for a failed vectorization task