Code Coverage on Lambda Expressions

What I think you mean is that the debugger is not stepping over the indicated line; is that right?

If that's your question, then the answer is that, at least in this particular case, what you are seeing is deferred execution. All of the LINQ extension methods provided by System.Linq.Enumerable exhibit this behavior: namely, the code inside the lambda statement itself is not executed on the line where you are defining it. The code is only executed once the resulting object is enumerated over.

Add this beneath the code you have posted:

foreach (var x in this.LanguageListItems)
{
    var local = x;
}

Here, you will see the debugger jump back to your lambda.