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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 alpha3(self, code):
 """ Return the ISO 3166-1 three letter country code matching the provided country code. If no match is found, returns an empty string. """

        code = self.alpha2(code)
        try:
            return self.alt_codes[code][0]
        except KeyError:
            return ""