def _find_interface(self, dev, setting):
    interfaces = find_interfaces(dev, bInterfaceClass=254, bInterfaceSubClass=3)
    if (not interfaces):
        raise ValueError('USB TMC interface not found.')
    elif (len(interfaces) > 1):
        pass
    return interfaces[0]
def _find_interface(self, dev, setting):
    interfaces = find_interfaces(dev, bInterfaceClass=254, bInterfaceSubClass=3)
    if (not interfaces):
        raise ValueError('USB TMC interface not found.')
    elif (len(interfaces) > 1):
        pass
    return interfaces[0]