export declare class SetOf<T> {
    private instancesOf;
    private items;
    private protectedItems;
    constructor(instancesOf: T | Function | Object | Array<T | Function | Object>);
    get empty(): boolean;
    get first(): T | null;
    forEach(action: Function | any): void;
    filter(action: Function | any): T[];
    find(action: Function | any): T;
    get last(): any;
    get length(): number;
    get size(): number;
    add(items: T | T[] | SetOf<T>, protect?: boolean): boolean;
    remove(items: T | T[] | SetOf<T>): boolean;
    delete(items: T | T[] | SetOf<T>): boolean;
    set(items: T | T[] | SetOf<T>, protect?: boolean): any | boolean;
    get(length?: number): T[];
    clear(): boolean;
    contains(item: T): boolean;
    has(item: T): boolean;
}