1export interface Callback<T> { 2 (data: T): void; 3} 4 5export interface ErrorCallback<T extends Error = BusinessError> { 6 (err: T): void; 7} 8 9export interface AsyncCallback<T> { 10 (err: BusinessError, data: T): void; 11} 12 13export interface BusinessError extends Error { 14 code: number; 15} 16