ng with the search window.
   * @param {Array.<!tr.model.TimedEvent>} networkRequests - Resource
   * requests overlapping with the search window.
   * @returns {number|undefined}
   */
  function findInteractiveTime(searchBegin, searchEnd,
      domContentLoadedEnd, longTasksInWindow, networkRequests) {
    // It is sufficient to only look at the end points of long tasks and network
    // requests. These are the points where any meaningful changes happen.
    const longTaskEndpoints = getEndpoints_(longTa