code: public void fetch(final String filter, final TileFunction<VectorTile> callback) {
  		final GetVectorTileRequest request = createRequest(filter);
  		GwtCommand command = new GwtCommand(GetVectorTileRequest.COMMAND);
  		command.setCommandRequest(request);
  		final VectorTile self = this;
  		lastRequest = request;
  		deferred = GwtCommandDispatcher.getInstance().execute(command,
  				new AbstractCommandCallback<GetVectorTileResponse>() {
  
  					public void execute(GetVectorTileResponse tileResponse) {
  						if (null == deferred || !deferred.isCancelled()) {
  							org.geomajas.layer.tile.VectorTile tile = tileResponse.getTile();
  							for (TileCode relatedTile : tile.getCodes()) {
  								codes.add(relatedTile);
  							}
  							code = tile.getCode();
  							contentType = tile.getContentType();
  							featureContent.setContent(tile.getFeatureContent());
  							labelContent.setContent(tile.getLabelContent());
  							try {
  								callback.execute(self);
  							} catch (Throwable t) {
  								Log.logError("VectorTile: error calling the callback after a fetch.", t);
  							}
  						}
  						deferred = null;
  					}
  				});
  	}
docs: Fetch all data related to this tile.
  
  @param filter When fetching it is possible to filter the data with this filter object. Null otherwise.
  @param callback When this node's data comes from the server, it will be handled by this callback function.