def deferred_to_columns(self):
        columns = {}
        self.deferred_to_data(columns, self.deferred_to_columns_cb)
        return columns
Converts the self.deferred_loading data structure to mapping of table
dataset/ETHPy150Open CollabQ/CollabQ/vendor/django/db/models/sql/query.py/BaseQuery.deferred_to_columns