Return the model associated with a specific name.
        Raises KeyError in case the model doesn't exist.
        :param name: model name to fetch
        :return: Python object representing the model

def get_model(self, name):
        """
        Return the model associated with a specific name.
        Raises KeyError in case the model doesn't exist.
        :param name: model name to fetch
        :return: Python object representing the model
        """
        try:
            ret = self.es.get(index=self.index_name, doc_type=self.DOC_TYPE,
                              id=name, _source=self.PACKAGE_FIELDS)
            if ret['found']:
                return ret['_source']['model']
            raise KeyError(name)
        except NotFoundError:
            raise KeyError(name)