Too much DRY

gistfile1.cs

public static T NullArgumentLogAndThrow<T>(this ILog log, T arg)
{
    if (arg.IsNotNull()) return arg;

    // get calling method
    var ex = new ArgumentNullException(typeof(T).Name);
    log.Fatal(new StackTrace().GetFrame(1).GetMethod().Name, ex);
    log.Fatal(new StackTrace().ToString());
    throw ex;
} 

//...

this.requestMapper = log.NullArgumentLogAndThrow(requestMapper);