code: public static final byte[] cloneSubArray(byte[] data, int offset, int size)
     {
        byte[] newData = new byte[size];
        System.arraycopy(data, offset, newData, 0, size);
        return (newData);
     }
docs: This method allows a subsection of a byte array to be copied.
  
  @param data source data
  @param offset offset into the source data
  @param size length of the source data to copy
  @return new byte array containing copied data