import { IZSort, ZSortDirection } from './sort.mjs';
import { IZSorter } from './sorter.mjs';
/**
 * Represents a sorter that simulates a single sort at a time.
 */
export declare class ZSorterSingle implements IZSorter {
    private _sorted;
    /**
     * Initializes a new instance of this object.
     *
     * @param initial -
     *        The initial sort list.
     */
    constructor(initial?: IZSort[]);
    index(subject?: string): number;
    sorted(subject?: string): ZSortDirection | undefined;
    sort(subject?: string): IZSort[];
}