What's the NetworkConnector for?

[gajus]

It is defined here, but I cannot see it being used anywhere:

swr-eth-tutorial/src/connectors/index.ts

Lines 10 to 14 in 88bf219

	export const network = new NetworkConnector({
	urls: { 1: RPC_URLS[1], 4: RPC_URLS[4] },
	defaultChainId: 1,
	pollingInterval: POLLING_INTERVAL,
	});