public void RegisterSerializer_RegisterSpecificSerializer_RegisteredSuccessfully()
        {
            // Arrange
            var mongoDatabaseBuilder = new MongoDatabaseBuilder(_mongoOptions);
            var arrangedSerializer   = new SimpleStringRegisteredSerializer();

            mongoDatabaseBuilder.RegisterSerializer <SimpleString>(arrangedSerializer);

            // Act
            mongoDatabaseBuilder.Build();

            // Assert
            IBsonSerializer <SimpleString> registeredSerializer =
                BsonSerializer.LookupSerializer <SimpleString>();

            Assert.True(registeredSerializer is SimpleStringRegisteredSerializer);
        }