@classmethod
    def override_column_headers(self, ar, **kwargs):
        return kwargs
Tell child cells to send us capacities.  This is typically
dataset/ETHPy150Open lsaffre/lino/lino/core/actors.py/Actor.override_column_headers--crossover with--dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/cells/messaging.py/MessageRunner.ask_children_for_capacities