code: public void doSuggestOpenSearch(StaplerRequest req, StaplerResponse rsp, @QueryParameter String q) throws IOException, ServletException {
          rsp.setContentType(Flavor.JSON.contentType);
          DataWriter w = Flavor.JSON.createDataWriter(null, rsp);
          w.startArray();
          w.value(q);
  
          w.startArray();
          for (SuggestedItem item : getSuggestions(req, q))
              w.value(item.getPath());
          w.endArray();
          w.endArray();
      }
docs: Used by OpenSearch auto-completion. Returns JSON array of the form:
  
  <pre>
  ["queryString",["comp1","comp2",...]]
  </pre>
  
  See http://developer.mozilla.org/en/docs/Supporting_search_suggestions_in_search_plugins