def get_keys_to_reserve(self):
    return []
Use this method to add extra d3 properties to your chart.
dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-compat/exported_appengine_sdk/google/appengine/tools/bulkloader.py/Loader.get_keys_to_reserve--crossover with--dataset/ETHPy150Open areski/python-nvd3/nvd3/NVD3Chart.py/NVD3Chart.add_chart_extras