def add_mongo_config(app, simple_connection_string,
                     mongo_uri, collection_name):
    """
    Configure the application to use MongoDB.

    :param app: Flask application
    :param simple_connection_string:
                Expects host:port:database_name or database_name
                Mutally_exclusive with mongo_uri
    :param mongo_uri: Expects mongodb://... as defined
                in https://docs.mongodb.com/manual/reference/connection-string/
                Mutually exclusive with simple_connection_string (must be None)
    :param collection_name: The collection containing Sacred's runs
    :return:
    """
    if mongo_uri != (None, None):
        add_mongo_config_with_uri(app, mongo_uri[0], mongo_uri[1],
                                  collection_name)
        if simple_connection_string is not None:
            print("Ignoring the -m option. Overridden by "
                  "a more specific option (-mu).", file=sys.stderr)
    else:
        # Use the default value 'sacred' when not specified
        if simple_connection_string is None:
            simple_connection_string = "sacred"
        add_mongo_config_simple(app, simple_connection_string, collection_name)
Configure the application to use MongoDB.

    :param app: Flask application
    :param simple_connection_string:
                Expects host:port:database_name or database_name
                Mutally_exclusive with mongo_uri
    :param mongo_uri: Expects mongodb://... as defined
                in https://docs.mongodb.com/manual/reference/connection-string/
                Mutually exclusive with simple_connection_string (must be None)
    :param collection_name: The collection containing Sacred's runs
    :return: