def _map_latest_release_options(release_option: str) ->str:
    """Overwrite Iris release options to be compatible with mozdownload."""
    if release_option == 'beta':
        return 'latest-beta'
    elif release_option == 'release':
        return 'latest'
    elif release_option == 'esr':
        return 'latest-esr'
    else:
        return 'nightly'
