anchor.diff:      await collection.insert({"my_field": n, "str_field": "str_$n"});
     }
   
  -  var result = await collection.find(where.gt("my_field", 5).sortBy('my_field'))
  +  var result = await collection
  +      .find(where.gt("my_field", 5).sortBy('my_field'))
         .toList();
     expect(result.length, 4);
     expect(result[0]['my_field'], 6);
  
positive.code:     {"name": "Nick", "score": 5}
    ]);
  
    var result = await collection.findOne(
        where.eq('name', 'Vadim').fields(['score']));
  
    expect(result['name'], isNull);
    expect(result['score'], 4);
  
negative.code:   expect(newCursor, isNotNull);
  }
  
  void testDbCommandCreation() {
    DbCommand dbCommand = new DbCommand(db, "student", 0, 0, 1, {}, {});
    expect('mongo_dart-test.student', dbCommand.collectionNameBson.value);
  }
  
  Future testPingDbCommand() async {
    DbCommand pingCommand = DbCommand.createPingCommand(db);
  
    var result = await db.queryMessage(pingCommand);
  
    expect(result.documents[0], containsPair('ok', 1));
  }
  
  Future testDropDbCommand() async {
    DbCommand command = DbCommand.createDropDatabaseCommand(db);
  
    var result = await db.queryMessage(command);
  
    expect(result.documents[0]["ok"], 1);
  }
  
  Future testIsMasterDbCommand() async {
    DbCommand isMasterCommand = DbCommand.createIsMasterCommand(db);
  
    var result = await db.queryMessage(isMasterCommand);
  
    expect(result.documents[0], containsPair('ok', 1));
  }
  
  testAuthComponents() {
  