import Period from "../Period";
export interface ISorter {
    sort(): Period[] | Date[];
}
export declare abstract class Sorter {
    protected _periods: Period[];
    protected _dates: Date[];
    constructor(periods?: Period[], dates?: Date[]);
    get periods(): Period[];
    get dates(): Date[];
    protected static sortAscending(firstVal: number, secondVal: number): number;
    protected static sortDescending(firstVal: number, secondVal: number): number;
}