code: @Override
      public void draw() {
          if (displayerSettings == null) {
              getView().errorMissingSettings();
          }
          else if (dataSetHandler == null) {
              getView().errorMissingHandler();
          }
          else if (!isDrawn()) {
              try {
                  drawn = true;
                  getView().showLoading();
  
                  beforeLoad();
                  beforeDataSetLookup();
                  dataSetHandler.lookupDataSet(new DataSetReadyCallback() {
                      public void callback(DataSet result) {
                          try {
                              dataSet = result;
                              afterLoad();
                              afterDataSetLookup(result);
                              createVisualization();
                              getView().showVisualization();
  
                              // Set the id of the container panel so that the displayer can be easily located
                              // by testing tools for instance.
                              String id = getDisplayerId();
                              if (!StringUtils.isBlank(id)) {
                                  getView().setId(id);
                              }
                              // Draw done
                              afterDraw();
                          } catch (Exception e) {
                              // Give feedback on any initialization error
                              showError(new ClientRuntimeError(e));
                          }
                      }
                      public void notFound() {
                          getView().errorDataSetNotFound(displayerSettings.getDataSetLookup().getDataSetUUID());
                      }
  
                      @Override
                      public boolean onError(final ClientRuntimeError error) {
                          showError(error);
                          return false;
                      }
                  });
              } catch (Exception e) {
                  showError(new ClientRuntimeError(e));
              }
          }
      }
docs: Draw the displayer by executing first the lookup call to retrieve the target data set