def flush(self):
        self.flushes += 1
Yield vdi_recs for each element in a VDI chain.
dataset/ETHPy150Open twisted/twisted/twisted/logger/test/test_file.py/DummyFile.flush--crossover with--dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/virt/xenapi/vm_utils.py/_walk_vdi_chain