void Init(TestArgs args) {
			constructor_ = null;
			options_ = new Options();

			options_.block_restart_interval = args.restart_interval;
			// Use shorter block size for tests to exercise block boundary
			// conditions more.
			options_.block_size = 256;
			if (args.reverse_compare) {
				options_.comparator = reverse_key_comparator;
			}
			switch (args.type) {
			case TABLE_TEST:
				constructor_ = new TableConstructor(options_.comparator);
				break;
			case BLOCK_TEST:
				constructor_ = new BlockConstructor(options_.comparator);
				break;
			case MEMTABLE_TEST:
				constructor_ = new MemTableConstructor(options_.comparator);
				break;
			case DB_TEST:
				constructor_ = new DBConstructor(options_.comparator);
				break;
			}
		}