'Simulate dbus.Interface'

def get_interface(self):

    def interface_side_effect(proxy, dbus_interface=None):
        if (proxy == self.network_manager_proxy):
            return self.network_manager
        elif (proxy == self.device_proxy_0):
            self.device_0.Get.side_effect = self.get_device_property(self.device_0)
            return self.device_0
        elif (proxy == self.device_proxy_1):
            self.device_1.Get.side_effect = self.get_device_property(self.device_1)
            return self.device_1
    return interface_side_effect
