code: void onDataSetSelected() {
          String selectedUUID = view.getSelectedDataSetId();
          for (DataSetDef dataSetDef : _dataSetDefList) {
              if (dataSetDef.getUUID().equals(selectedUUID)) {
                  fetchMetadata(selectedUUID,
                                new RemoteCallback<DataSetMetadata>() {
  
                                    public void callback(DataSetMetadata metadata) {
                                        dataSetLookup = lookupConstraints.newDataSetLookup(metadata);
                                        updateDataSetLookup();
                                        changeEvent.fire(new DataSetLookupChangedEvent(dataSetLookup));
                                    }
                                });
              }
          }
      }
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