exampleTest.cs

using Xunit;


public class MyTests 
{
  
  [Fact] //This means this is a test
  public void TestMyGetMethodWorks()
  {
      var journalService = new JournalService(/* not sure what kinda constructor you have */);
      
      
      var resultJournal = journalService.Get(new JournalServiceRequestDTO { Id = 4; });
      
      //just make sure it's actually returning the journal with Id = 4
      Assert.Equal(4, resultJournal.Id);
  }
}