def get_class_namespace(cls):
    """
    Resolve the full qualified namespace of a class.
    This support multiple inheritance using Python's method resolution order.

    >>> from omtk.rigs.rigArm import Arm
    >>> get_class_namespace(Arm)
    'Module.Limb.Arm'

    :param cls: A class definition to inspect.
    :return: A str instance representing the full qualified class namespace.
    """
    if not hasattr(cls, '__mro__'):
        raise NotImplementedError("Class {0} is a Python old-style class and is unsupported.".format(cls))

    return '.'.join(
        reversed([subcls.__name__ for subcls in cls.__mro__ if subcls != object])
    )