code: public byte[] getByteArrayValue(int index)
     {
        byte[] result = null;
  
        if (m_array[index] != null)
        {
           result = (byte[]) m_array[index];
        }
  
        return (result);
     }
docs: This method retrieves a byte array containing the data at the
  given index in the block. If no data is found at the given index
  this method returns null.
  
  @param index index of the data item to be retrieved
  @return byte array containing the requested data