/**
 * Converts timestamps to approximate wall times ensuring they are monotonically increasing.
 *
 * Per [Chromium Source](https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/platform/loader/fetch/resource_load_timing.h)
 * > We want to present a unified timeline to Javascript. Using walltime is
 *    problematic, because the clock may skew while resources load. To prevent
 *    that skew, we record a single reference walltime when root document
 *    navigation begins. All other times are recorded using
 *    monotonicallyIncreasingTime(). When a time needs to be presented to
 *    Javascript, we build a pseudo-walltime using the following equation
 *    (m_requestTime as example):
 *      pseudo time = document wall reference +
 *                        (m_requestTime - document monotonic reference).
 */
export declare class TimeLord {
    #private;
    /**
     * Collect timestamp/wall-time pairs from Chrome DevTools Protocol events so that
     * range of differences of (wallTime - timestamp) can be calculated.
     */
    addTimestampWallTimePair: ({ timestamp, wallTime }: {
        timestamp: number;
        wallTime: number;
    }) => void;
    /**
     * Wall times are not always monotonically increasing because of adjustments that may
     * cause seconds to be repeated or be skipped.
     *
     * Timestamps are guaranteed to be monotonically increasing over time, but do not have
     * a fixed relationship to wall time.
     *
     * This method converts a timestamp to an approximate walltime, by taking the wall time at the
     * pair with the earliest observed timestamp, then adding the number of milliseconds that has
     * passed between that earliest timestamp and the parameter passed to this method.
     * @param timestamp A monotonically increasing timestamp to convert to an approximate wall time.
     * @returns A wall time
     */
    getApproximateWallTimeInSecondsFromUnixEpochFromMonotonicallyIncreasingTimestamp: (timestamp: number) => number;
    get commentOnSkew(): string;
}