time multidimensional view path object.
   *
   * @param {!Array.<!Array.<string>>} previousPath
   * @returns {!Array.<!Array.<string>>}
   */
  function clonePath_(previousPath) {
    return previousPath.map(subPath => subPath.map(x => x));
  }


  /**
   * Returns an object containing the processType, threadType, railStage, and
   * initiatorType encoded in the provided CPU time multidimensional view path
   * object. Decoding the path into this object can make code easier to
   * understand than indexin