def __call__(xCqNck7t, *args, **kwargs):
    """Dict(key=val) creates a new dict with the key:val. That has always been true for 
        initializing a new Dict. But now, this pattern also works for an existing Dict. 
        For example:
        >>> d1 = Dict(a=1, b=2); d2 = d1(c=3); d1; d2
        {'a': 1, 'b': 2}
        {'a': 1, 'b': 2, 'c': 3}
        >>> 
        Note that d1 has not been changed -- this method creates a new dict based
        on the old one without changing the old one.
        """
    d = xCqNck7t.__class__(*args, **xCqNck7t)
    d.update(**kwargs)
    return d
