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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 to(self, currency):
 """Return equivalent money object in another currency"""

        if currency == self._currency:
            return self
        rate = xrates.quotation(self._currency, currency)
        if rate is None:
            raise ExchangeRateNotFound(xrates.backend_name,
                                         self._currency, currency)
        amount = self._amount * rate
        return self.__class__(amount, currency)