import { Provider, HDNodeWallet } from 'ethers';
import { Logger, Metrics } from '@graphprotocol/common-ts';
import { DocumentNode } from 'graphql';
export declare const parseBoolean: (val: string | boolean | number | undefined | null) => boolean;
export declare function nullPassThrough<T, U>(fn: (x: T) => U): (x: T | null) => U | null;
export declare function getTestProvider(network: string): Provider;
export declare function monitorEthBalance(logger: Logger, wallet: HDNodeWallet, metrics: Metrics, networkIdentifier: string): Promise<void>;
export declare function mergeSelectionSets(first: DocumentNode, second: DocumentNode): DocumentNode;
export declare const sleep: (ms: number) => Promise<unknown>;
export declare function tryParseCustomError(error: unknown): string | unknown;
export declare function chunk<T>(array: T[], size: number): T[][];