How to use the fabric-network/lib/impl/event/checkpointfactories.FILE_SYSTEM_CHECKPOINTER function in fabric-network

this.networks = new Map();

		// default options
		this.options = {
			queryHandlerOptions: {
				strategy: QueryStrategies.MSPID_SCOPE_SINGLE
			},
			eventHandlerOptions: {
				commitTimeout: 300, // 5 minutes
				strategy: EventStrategies.MSPID_SCOPE_ALLFORTX
			},
			discovery: {
				enabled: Client.getConfigSetting('initialize-with-discovery', true)
			},
			checkpointer: {
				factory: CheckpointFactories.FILE_SYSTEM_CHECKPOINTER,
				options: {}
			},
			eventHubSelectionOptions: {
				strategy: EventHubSelectionStrategies.MSPID_SCOPE_ROUND_ROBIN,
			}
		};
	}