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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def merged(cls, *flatterms: 'FlatTerm') -> 'FlatTerm': """Concatenate the given flatterms to a single flatterm. Args: *flatterms: The flatterms which are concatenated. Returns: The concatenated flatterms. """

        return cls(cls._combined_wildcards_iter(sum(flatterms, cls.empty())))