angular/modules/@angular/router/src/lifecycle_reflector.ts

import {Type, isBlank} from './facade/lang';

export function hasLifecycleHook(name: string, obj: Object): boolean {
  if (isBlank(obj)) return false;
  let type = obj.constructor;
  if (!(type instanceof Type)) return false;
  return name in(<any>type).prototype;
}