def register_all(self, tasks):
        assert not self._did_create
        for task in tasks:
            self.register(task)
Return the total number of headers, including duplicates.
dataset/ETHPy150Open facebook/sparts/sparts/vtask.py/Tasks.register_all--crossover with--dataset/ETHPy150Open kleientertainment/ds_mod_tools/pkg/win32/Python27/Lib/email/message.py/Message.__len__