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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 specialize(self, domain):
 """Specialize ``self`` to a concrete domain. """

        if domain == self.domain:
            return self

        return type(self)(
            dtype=self.dtype,
            missing_value=self.missing_value,
            dataset=self._dataset.specialize(domain),
            name=self._name,
            doc=self.__doc__,
            metadata=self._metadata,
        )