@abc.abstractmethod
    def __getitem__(self, key):
Wait for a node to get created and the provision it.
dataset/ETHPy150Open peterhudec/authomatic/authomatic/extras/interfaces.py/BaseSession.__getitem__--crossover with--dataset/ETHPy150Open ClusterHQ/flocker/admin/acceptance.py/LibcloudRunner._provision_with_retry