import BigNumber from 'bignumber.js';
/**
 * Convert string, number, or BigNumber to byte array
 * @param val - value to convert
 * @param big - enables force conversion to BigNumber
 * @returns Buffer
 * @category utils
 * @deprecated use `Buffer.from(<string>)` or `Buffer.from(<number>.toString(16), 'hex')` instead
 */
export declare function toBytes(val?: null | string | number | BigNumber, big?: boolean): Buffer;