code: public void init(QueryHandler handler, float minDistance, boolean morePopular) throws IOException
     {
        if (handler instanceof SearchIndex)
        {
           this.spellChecker = new InternalSpellChecker((SearchIndex)handler, minDistance, morePopular);
        }
        else
        {
           throw new IOException("LuceneSpellChecker only works with " + SearchIndex.class.getName());
        }
     }
docs: {@inheritDoc}