def METHOD_NAME(self, mbed_lstools_mock):
    """
    Test that checks function returns correctly when no mount point is supplied.
    :param mbed_lstools_mock: Mocks Mbed LS tools with MbedLsToolsMock
    :return 
    """
    interface_version = get_interface_version(self.missing_mount_point)
    assert interface_version == 'unknown'