export default class ReactiveDependency { private _accessor; addDependency: (targetObj: Text | HTMLElement, dep: (() => void)) => void; get value(): T; set value(val: T); constructor(_accessor: { get: () => T; set: (val: T) => void; }, addDependency: (targetObj: Text | HTMLElement, dep: (() => void)) => void); derive(fn: (value: T) => U): ReactiveDependency; }