public boolean isEmpty() {
    return this instanceof EmptyStatObject;
  }
format 1.536834943435905E12 (nano seconds) to 1536834943435 (ms)
and convert timestamp to milliseconds

@param s raw String obtained from getStats.

@return the formatted timestamp
KITE-Framework/src/main/java/org/webrtc/kite/stats/rtc/RTCSingleStatObject.java