export function formatSecondsSinceEpoch(sse: any): string;
/**
 * Create a derived store where all the object keys are prefixed.
 * ```
 * { a: 1, b: 2 } -> { foo_a: 1 foo_b: 2 } // prefix: foo_
 * ```
 * @param {writable} store we derive from
 * @param {string} prefix for each key
 * @returns {writable}
 */
export function keyPrefixStore(store: typeof writable, prefix: string): typeof writable;
export const dateFormatter: Intl.DateTimeFormat;
import { writable } from "svelte/store";