Интерфейс IComputed

interface IComputed {
    struct: (
        target: Object,
        key: string | symbol,
        baseDescriptor?: PropertyDescriptor,
    ) => void;
    <T>(options: IComputedValueOptions<T>): any;
    <T>(func: () => T, setter: (v: T) => void): IComputedValue<T>;
    <T>(func: () => T, options?: IComputedValueOptions<T>): IComputedValue<T>;
    (
        target: Object,
        key: string | symbol,
        baseDescriptor?: PropertyDescriptor,
    ): void;
}