NullAnalyzer still tokenizes fields

[Polina Litvak]

I tried to create my own analyzer so it returns fields as they are
(without any tokenizing done), using code posted on lucene-user a short
while a go:
 
private static class NullAnalyzer
   extends Analyzer
    {
      public TokenStream tokenStream(String fieldName, Reader reader)
      {
        return new CharTokenizer(reader)
        {
          protected boolean isTokenChar(char c)
          {
            return true;
          }
        };
     }
 }
 
 
After testing this analyzer I found out that fields I pass to it still
get tokenized. 
E.g. I have a field with value ABCD-EF. When passing it through the
analyzer, the only characters that end up in isTokenChar() are "A, B, C,
D, E, F". So looks like "-" gets filtered out before it even gets to
isTokenChar().
 
Did anyone encounter this problem ? 
Any help will be greatly appreciated!
 
Thanks,
Polina