import { PipeTransform } from '@angular/core';
import { MdlTreeSelectDirective } from '../directives/tree-select.directive';
import * as i0 from "@angular/core";
export declare class MdlTreeSelectSummaryPipe implements PipeTransform {
    transform(val: any, treeSelect: MdlTreeSelectDirective<any, any>): string | null;
    private addOptions;
    static ɵfac: i0.ɵɵFactoryDeclaration<MdlTreeSelectSummaryPipe, never>;
    static ɵpipe: i0.ɵɵPipeDeclaration<MdlTreeSelectSummaryPipe, "mdlTreeSelectSummary", true>;
}