code: public void copyBytesTo(byte[] dest, int destOffset) {
      BigendianEncoding.longToByteArray(idHi, dest, destOffset);
      BigendianEncoding.longToByteArray(idLo, dest, destOffset + BigendianEncoding.LONG_BYTES);
    }
docs: Copies the byte array representations of the {@code TraceId} into the {@code dest} beginning at
  the {@code destOffset} offset.
  
  @param dest the destination buffer.
  @param destOffset the starting offset in the destination buffer.
  @throws NullPointerException if {@code dest} is null.
  @throws IndexOutOfBoundsException if {@code destOffset+TraceId.SIZE} is greater than {@code
  dest.length}.
  @since 0.5