public void Setup()
{
correlation = new Correlation(CorrelationId, CallerId);
log = Substitute.For<ILog>();
logger = Substitute.For<log4net.Core.ILogger>();
log.Logger.Returns(logger);
repository = Substitute.For<ILoggerRepository>();
repository.GetLogger(source.GetType()).Returns(log);
sut = new LogWriter(repository, source);
}