code: protected void pad() throws IOException {
          if (bytesWritten > 0) {
              int extra = (int) ( bytesWritten % TarConstants.DATA_BLOCK );
  
              if (extra > 0) {
                  write( new byte[TarConstants.DATA_BLOCK - extra] );
              }
          }
      }
docs: Pads the last content block
  
  @throws IOException