Read dashboard content.

        Args:
            dash_id: dashboard id.

        Returns:
            A dict containing the content of that dashboard, not include the meta info.

def get(self, dash_id):
        """Read dashboard content.

        Args:
            dash_id: dashboard id.

        Returns:
            A dict containing the content of that dashboard, not include the meta info.
        """
        data = json.loads(r_db.hmget(config.DASH_CONTENT_KEY, dash_id)[0])
        return build_response(dict(data=data, code=200))