def __init__(self, df=None, **properties):
        if df is not None:
            self._df = df
        super(ColumnAssigner, self).__init__(**properties)
Handles loading all of the tasks for a given `imported` module
dataset/ETHPy150Open bokeh/bokeh/bokeh/charts/data_source.py/ColumnAssigner.__init__--crossover with--dataset/ETHPy150Open prestodb/presto-admin/prestoadmin/main.py/load_tasks_from_module