import Ethereum from "./ethereum";
import SmartContract from "./smartContract";
/**
 * toolkit of erc20
 *
 * @class ERC20
 */
declare class ERC20 extends SmartContract {
    /**
     * Creates an instance of ERC20
     * @memberof ERC20
     */
    constructor();
    /**
     * init instance of erc20 contract
     *
     * @param {string} contractAddress contract address of erc20 token
     * @memberof ERC20
     */
    init(contractAddress: string, ethereum: Ethereum): void;
    /**
     * destroy instance of erc20 contract
     *
     * @memberof ERC20
     */
    destroy(): void;
    /**
     * request decimals of erc20 token
     *
     * @returns {Promise<number>}
     * @memberof ERC20
     */
    decimals(): Promise<number>;
    /**
     * request balance of erc20 token
     *
     * @param {string} address ethereum address
     * @returns {Promise<string>} resolve "0" if request failed
     * @memberof ERC20
     */
    balanceOf(address: string): Promise<string>;
    /**
     * transfer token to erc20 contract address
     *
     * @param {string} secret ethereum secret of sender address
     * @param {string} to address of destination
     * @param {string} amount amount
     * @param {string} [nonce] nonce
     * @returns {Promise<string>} resolve hash if success
     * @memberof ERC20
     */
    transfer(secret: string, to: string, amount: string, nonce?: number): Promise<string>;
}
export default ERC20;