Extract terms not by reader, but by documents

[Rafael Rossini]

Hi all,

    In some custom highlighting, I often write a code like this:

       Set<Term> matchedTerms = new HashSet<Term>();
       query.rewrite(reader).extractTerms(matchedTerms);

    With this code the Term Set gets populated by the matched query in your
whole index. Is it possible to this with a document instead of the reader?
Something like
query.rewrite(documentId).extractTerms(matchedTerms) ?

[]s
     Rossini