def list_prs_arguments(parser):
    """ List pull requests.
    """
    parser.add_argument('indexname', type=str, action='store', nargs='?',
        help=
        'index name, specified as NAME or USER/NAME.  If no index is specified use the current index'
        )
    parser.add_argument('-a', '--all-states', action='store_true', help=
        'Output normally hidden states.')
    parser.add_argument('-m', '--messages', action='store_true', help=
        'Include state change messages in output.')
