#define DEBUG
using System;
using System.Diagnostics;

namespace ClassExamples {
   public class Trace {
      [Conditional("DEBUG")] public static void Msg(string msg) {
         Console.WriteLine(msg);
      }
   }

   class Test {
      static void A( ) { Trace.Msg("Now in A."); B( ); }
      static void B( ) { Trace.Msg("Now in B."); }

      public static void Main( ) {
         Trace.Msg("Now in Main.");
         A( );
         Console.WriteLine("Done.");
      }
   }
}