Produce an array that contains the union: each distinct element
        from all of the passed-in arrays.

def union(self, *args):
        """
        Produce an array that contains the union: each distinct element
        from all of the passed-in arrays.
        """
        # setobj = set(self.obj)
        # for i, v in enumerate(args):
        #     setobj = setobj + set(args[i])
        # return self._wrap(self._clean._toOriginal(setobj))
        args = list(args)
        args.insert(0, self.obj)
        return self._wrap(_.uniq(self._flatten(args, True, [])))