message: Move `isToken` property into interface
diff: @@ -47,6 +47,7 @@ export class AccountCoin extends BaseCoin {
  export interface Erc20ConstructorOptions extends AccountConstructorOptions {
  contractAddress: string;
  + isToken: true;
  }
  export interface ContractAddress extends String {
  @@ -58,7 +59,6 @@ export class Erc20Coin extends AccountCoin {
  constructor(options: Erc20ConstructorOptions) {
  super({
  - isToken: true,
  ...options,
  });
  