public static Ranker getRankerByArguments(CgiArguments arguments,
				Options options, Indexer indexer) {
			switch (arguments._rankerType) {
			case FULLSCAN:
				return new RankerFullScan(options, arguments, indexer);
			case CONJUNCTIVE:
				return new RankerConjunctive(options, arguments, indexer);
			case FAVORITE:
				return new RankerFavorite(options, arguments, indexer);
			case COMPREHENSIVE:
				return new RankerComprehensive(options, arguments, indexer);
			case COSINE:
				// Plug in your cosine Ranker
				break;
			case QL:
				// Plug in your QL Ranker
				break;
			case PHRASE:
				// Plug in your phrase Ranker
				break;
			case LINEAR:
				// Plug in your linear Ranker
				break;
			case NONE:
				// Fall through intended
			default:
				// Do nothing.
			}
			return null;
		}