/**
 * Tests whether _any_ portion of the el is visible.
 * @param el HTML element
 */
export declare function isInViewport(el: HTMLElement): boolean;
export declare function drawChart(chartDiv: HTMLDivElement, functionName: string, unit: string, objects: string[], columnData: (number | null)[][]): void;
export interface ErrorWithMessage {
    message: string;
}