code: public static StringBuilder elapsedAndSize(long startTimeNanos, long endTimeNanos, long size) {
          final StringBuilder buf = new StringBuilder(16);
          appendElapsedAndSize(buf, startTimeNanos, endTimeNanos, size);
          return buf;
      }
docs: Similar to {@link #appendElapsedAndSize(StringBuilder, long, long, long)} except that this method
  creates a new {@link StringBuilder}.