Query the client for available Volume Shadow Copies using a WMI query.

def Start(self):
    """Query the client for available Volume Shadow Copies using a WMI query."""
    self.state.shadows = []
    self.state.raw_device = None

    self.CallClient(
        server_stubs.WmiQuery,
        query="SELECT * FROM Win32_ShadowCopy",
        next_state="ListDeviceDirectories")