def get_all_bw_counters(self, instances):
        bw = []
        return bw
Get the flags to be added to the cflags for precompiled header support.
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/virt/fake.py/FakeDriver.get_all_bw_counters--crossover with--dataset/ETHPy150Open adobe/brackets-shell/gyp/pylib/gyp/msvs_emulation.py/MsvsSettings._GetPchFlags