/**
 * Copyright 2019 the orbs-ethereum-contracts authors
 * This file is part of the orbs-ethereum-contracts library in the Orbs project.
 *
 * This source code is licensed under the MIT license found in the LICENSE file in the root directory of this source tree.
 * The above notice should be included in all copies or substantial portions of the software.
 */
import Web3 from 'web3';
import { PromiEvent, TransactionReceipt } from 'web3-core';
import { IOrbsTokenService, OrbsAllowanceChangeCallback } from "./IOrbsTokenService";
import { TUnsubscribeFunction } from "../contractsTypes/contractTypes";
export declare class OrbsTokenService implements IOrbsTokenService {
    private web3;
    private erc20TokenContract;
    constructor(web3: Web3, erc20address?: string);
    setFromAccount(address: string): void;
    readBalance(address: string): Promise<bigint>;
    readAllowance(ownerAddress: string, spenderAddress: string): Promise<bigint>;
    subscribeToAllowanceChange(ownerAddress: string, spenderAddress: string, callback: OrbsAllowanceChangeCallback): TUnsubscribeFunction;
    approve(spenderAddress: string, amount: bigint): PromiEvent<TransactionReceipt>;
}