code: @Override
  	public void externalizeCacheObjectAsync(final String fileNamePrefix, final Object object,
  			final CreateCompletionCallback callback) {
  		_aggregator.getExecutors().getFileCreateExecutor().submit(new Runnable() {
  			File file = null;
  			public void run() {
  				try {
  					file = File.createTempFile(fileNamePrefix, ".cache", _directory); //$NON-NLS-1$
  					ObjectOutputStream os;
  					os = new ObjectOutputStream(new FileOutputStream(file));
  					try {
  						os.writeObject(object);
  					} finally {
  						try { os.close(); } catch (Exception ignore) {}
  					}
  					if (callback != null) {
  						callback.completed(file.getName(), null);
  					}
  				} catch (IOException e) {
  					if (log.isLoggable(Level.WARNING))
  						log.log(Level.WARNING, MessageFormat.format(
  								Messages.CacheManagerImpl_4, new Object[]{file.getPath()}), e);
  					if (callback != null) {
  						callback.completed(file != null ? file.getName() : null, e);
  					}
  				}
  			}
  		});
  	}
docs: /* (non-Javadoc)
  @see com.ibm.jaggr.service.cache.ICacheManager#externalizeObjectAsync(java.lang.String, java.lang.Object, com.ibm.jaggr.service.cache.ICacheManager.CreateCompletionCallback)