Wrapper function to allow calling any function
        using Value objects as parameters.

def _wrap(fn):
        """
        Wrapper function to allow calling any function
        using Value objects as parameters.
        """
        def _func(*args):
            merged = None
            _args = []
            for arg in args:
                if merged.__class__ != arg.__class__:
                    if merged is None:
                        merged = arg.__class__(None)
                    else:
                        merged = Value._merge_type(merged, arg)(None)
                merged.merge(arg)
                if isinstance(arg, Value):
                    arg = arg.value
                _args.append(arg)
            merged.value = fn(*_args)
            return merged
        return _func