import type { NumberOfMilliseconds, UnixTimestampMillis } from '../types';
/**
 * using _ = blockTimer()
 * // will log "took 1.234 sec" on dispose
 *
 * using _ = blockTimer('named')
 * // will log "named took 1.234 sec" on dispose
 *
 * @experimental
 */
export declare function _blockTimer(name?: string): Disposable;
/**
 * Returns time passed since `from` until `until` (default to Date.now())
 */
export declare function _since(from: UnixTimestampMillis, until?: UnixTimestampMillis): string;
/**
 * Returns, e.g:
 * 125 ms
 * 1.125 sec
 * 11 sec
 * 1m12s
 * 59m2s
 * 1h3m12s
 */
export declare function _ms(millis: NumberOfMilliseconds): string;