WatchBlockNumberOptions
type WatchBlockNumberOptions = {  latestBlockNumber?: bigint;  onError?: (error: Error) => void;  onNewBlockNumber: (blockNumber: bigint) => void;  overPollRatio?: number;};
type latestBlockNumber = bigint;
function onError(error: Error): void;
function onNewBlockNumber(blockNumber: bigint): void;
type overPollRatio = number;