public void AddToLog_Test(string message)
{
_uut.Writer = Substitute.For <StringWriter>();
_uut.AddToLog(message);
var expectedMessage = string.Format("{0:YYY:HH:mm:ss}: {1}", DateTime.Now, message);
// Get all _loggers Received calls from AddToLog where string argument matched
// Code example found at: https://stackoverflow.com/questions/52439697/how-to-check-any-of-multiple-overloads-called-nsubstitute
// Answer posted by: David Tchepak sep 22'18
var calls = _uut.Writer.ReceivedCalls()
.Where(x => x.GetMethodInfo().Name == nameof(_uut.Writer.WriteLine))
.Where(x => ((string)x.GetArguments()[0])
.Contains(expectedMessage));
// Check if number of expected arguments was found
Assert.AreEqual(1, calls.Count());
}