<book xmlns:its="http://www.w3.org/2005/11/its" its:version="2.0"> 
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 <verse id="firstverse"> 
 'Twas brillig, and the slithy toves
  Did gyre and gimble in the wabe;
 All mimsy were the borogoves,
  And the mome raths outgrabe.
 </verse> 
</book>