 Apparently nested packets that have a bytes attribute. Tester and scanner should
 agree on location of bad packet. Invalid bytes attribute error expected.                                      
          1         2         3         4         5         6         7         8         9       9
 3 345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678
 4                                                                                                |
 5           +++hB <?xpacket begin='' id='W5M0MpCehiHzreSzNTczkc9d' bytes="800"?>                 |
<?xpacket begin='' id='W5M0MpCehiHzreSzNTczkc9d'?><?xpacket end='r'?>---tB                        |
<?xpacket end='r'?>                                                                                
                                                                                                   
                                                                                                   
                                                                                                   
                                                                                                   
                                                                                                   
                   
          1         2         3         4         5         6         7         8         9       9
15 345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678