export default class CombinedSet<T> extends Set<T> {
    constructor(values?: readonly T[] | null);
    toArray(): T[];
    filter(predicate: (value: T, index: number, array: T[]) => boolean): CombinedSet<T>;
    map(predicate: (value: T, index: number, obj: T[]) => T): CombinedSet<T>;
    some(predicate: (value: T, index: number, array: T[]) => boolean): boolean;
    find(predicate: (value: T, index: number, obj: T[]) => boolean): T | undefined;
    findIndex(predicate: (value: T, index: number, obj: T[]) => boolean): number;
}