         # File lib/ferret/index.rb, line 191
    191:     def highlight(query, doc_id, options = {})
    192:       @dir.synchronize do
    193:         ensure_searcher_open()
    194:         @searcher.highlight(do_process_query(query),
    195:                             doc_id,
    196:                             options[:field]||@options[:default_field],
    197:                             options)
    198:       end
    199:     end