Get annotations for *cls*.

def _get_annotations(cls):
    """
    Get annotations for *cls*.
    """
    anns = getattr(cls, "__annotations__", None)
    if anns is None:
        return {}

    # Verify that the annotations aren't merely inherited.
    for base_cls in cls.__mro__[1:]:
        if anns is getattr(base_cls, "__annotations__", None):
            return {}

    return anns