code: private static void copyInRowKey(final byte[] row, final short offset,
        final byte[] bytes) {
      System.arraycopy(bytes, 0, row, offset, bytes.length);
    }
docs: Copies the specified byte array at the specified offset in the row key.
  
  @param row
  The row key into which to copy the bytes.
  @param offset
  The offset in the row key to start writing at.
  @param bytes
  The bytes to copy.