def METHOD_NAME(self) -> str:
    """Return the default catalog name.
    Returns: The name of the default catalog in `default-catalog`.
             Returns `default` when the key cannot be found in the config file.
    """
    if default_catalog_name := self.config.get(DEFAULT_CATALOG):
        if not isinstance(default_catalog_name, str):
            raise ValueError(f"Default catalog name should be a str: {default_catalog_name}")
        return default_catalog_name
    return DEFAULT