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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_dataset(self, dataset_key):
 """Retrieve an existing dataset definition This method retrieves metadata about an existing :param dataset_key: Dataset identifier, in the form of owner/id :type dataset_key: str :returns: Dataset definition, with all attributes :rtype: dict :raises RestApiException: If a server error occurs Examples -------- 'An Intro to data.world Dataset' """

        try:
            return self._datasets_api.get_dataset(
                *(parse_dataset_key(dataset_key))).to_dict()
        except _swagger.rest.ApiException as e:
            raise RestApiError(cause=e)