export declare class Collection<T extends Object> extends Array {
    ItemAdded?: (i: T) => void;
    ItemAddedBefore?: (i: T) => void;
    ItemSplice?: (start: number, i: T) => void;
    _map: Set<T>;
    add(item: T): number;
    addBefore(item: T): number;
    insert(start: number, item: T): any[];
    remove(item: T): void;
    item(key: T): T;
    has(item: T): boolean;
    clear(): void;
    itemIndex(index: number): T;
}
export declare class KeyValueItem {
    key: string;
    value: any;
}