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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 get_shared_file(self, sharekey=None):
 """ Returns a SharedFile object given by the sharekey. Args: sharekey (str):
 Sharekey of the SharedFile you want to retrieve. Returns: SharedFile """

        if not sharekey:
            raise Exception("You must specify a sharekey.")
        endpoint = '/api/sharedfile/{0}'.format(sharekey)
        data = self._make_request('GET', endpoint)
        return SharedFile.NewFromJSON(data)