import { ModifierPhases } from '@popperjs/core';
import ResizeObserver from 'resize-observer-polyfill';
export declare const modifiers: {
    /**
     *  observes for Popup component's **trigger** DOM element changes
     *  and updates popper styles.
     *
     *  For example if element's height was changed popup will
     *  update its position accordingly
     */
    triggerObserver: {
        name: string;
        enabled: boolean;
        phase: ModifierPhases;
        options: {
            resizeObserverInstance: ResizeObserver;
        };
        fn: () => void;
        effect: ({ state, options, instance }: any) => () => void;
    };
};
