export declare class Comparators {
    static byOrderIndexField: (a: any, b: any) => 1 | 0 | -1;
    static byKey<T>(key: keyof T, nullsLast?: boolean): (a: T, b: T) => (-1 | 1 | 0);
    static byField<T, C>(keyGetter: (item: T) => C, nullsLast?: boolean): (a: T, b: T) => (-1 | 1 | 0);
    static equals: (val1: any, val2: any) => boolean;
}