anchor.diff:  }
   
   main() {
  -//  hierarchicalLoggingEnabled = true;
  -//  Logger.root.level = Level.OFF;
  -//  new Logger('Db').level = Level.ALL;
  -//  var listener = (LogRecord r) {
  -//    var name = r.loggerName;
  -//    if (name.length > 15) {
  -//      name = name.substring(0, 15);
  -//    }
  -//    while (name.length < 15) {
  -//      name = "$name ";
  -//    }
  -//    print("${r.time}: $name: ${r.message}");
  -//  };
  -//  Logger.root.onRecord.listen(listener);
  -//
  -
     group('DbCollection tests:', () {
       test('testAuthComponents', testAuthComponents);
     });
     group('DBCommand:', () {
  +    setUp(() async {
  +      db = new Db(DefaultUri);
  +      await db.open();
  +    });
  +
  +    tearDown(() async {
  +      await db.collection(collectionName).drop();
  +      await db.close();
  +    });
  +
       test('testAuthentication', testAuthentication);
       test('testAuthenticationWithUri', testAuthenticationWithUri);
       test('testDropDatabase', testDropDatabase);
  
positive.code:   });
  }
  
  Future testGetNonce() {
    Db db = new Db('${DefaultUri}mongo_dart-test');
    return db.open().then((c) {
      return db.getNonce();
    }).then((v) {
      expect(v["ok"], 1);
      return db.close();
    });
  }
  
  Future getBuildInfo() {
    Db db = new Db('${DefaultUri}mongo_dart-test');
    return db.open().then((c) {
      return db.getBuildInfo();
    }).then((v) {
      expect(v["ok"], 1);
      return db.close();
    });
  }
  
  
  Future testIsMaster() {
    Db db = new Db('${DefaultUri}mongo_dart-test');
    return db.open().then((c) {
      return db.isMaster();
    }).then((v) {
      expect(v["ok"], 1);
      return db.close();
    });
  }
  
  testCollectionCreation() {
  
negative.code: import 'package:test/test.dart';
  
  const DefaultUri = 'mongodb://127.0.0.1:27017/';
  const String collectionName = 'collectionName';
  
  Db db;
  
  Future testGetCollectionInfos() {
    Db db = new Db(
  