GetCategories.
        [Preview API]
        :param str languages:
        :rtype: [str]

def get_categories(self, languages=None):
        """GetCategories.
        [Preview API]
        :param str languages:
        :rtype: [str]
        """
        query_parameters = {}
        if languages is not None:
            query_parameters['languages'] = self._serialize.query('languages', languages, 'str')
        response = self._send(http_method='GET',
                              location_id='e0a5a71e-3ac3-43a0-ae7d-0bb5c3046a2a',
                              version='5.1-preview.1',
                              query_parameters=query_parameters)
        return self._deserialize('[str]', self._unwrap_collection(response))