/**
* Return a query that will return docs like the passed lucene document ID.
*
* @param docNum the documentID of the lucene doc to generate the 'More Like This" query for.
* @return a query that will return docs like the passed lucene document ID.
*/
public Query like(int docNum) throws IOException {
if (fieldNames == null) {
// gather list of valid fields from lucene
Collection<String> fields = MultiFields.getIndexedFields(ir);
fieldNames = fields.toArray(new String[fields.size()]);
}
return createQuery(retrieveTerms(docNum));
}
