def plugin_settings(settings):
    """
    Modify the provided settings object with settings specific to this plugin.
    """
    settings.COMPLETION_AGGREGATOR_BLOCK_TYPES = {'course', 'chapter',
        'sequential', 'vertical'}
    settings.COMPLETION_AGGREGATOR_ASYNC_AGGREGATION = False
    settings.COMPLETION_AGGREGATOR_AGGREGATION_LOCK = (
        'COMPLETION_AGGREGATOR_AGGREGATION_LOCK')
    settings.COMPLETION_AGGREGATOR_CLEANUP_LOCK = (
        'COMPLETION_AGGREGATOR_CLEANUP_LOCK')
    settings.COMPLETION_AGGREGATOR_AGGREGATION_LOCK_TIMEOUT_SECONDS = 1800
    settings.COMPLETION_AGGREGATOR_CLEANUP_LOCK_TIMEOUT_SECONDS = 900
