docs: public static String stackTrace( Throwable t, String separator, int depth )
      {
          if (GreenPepper.isDebugEnabled()) depth = FULL;
          
          StringWriter sw = new StringWriter();
          sw.append( t.toString() );
          for (int i = 0; i < t.getStackTrace().length && i <= depth; i++)
          {
              StackTraceElement element = t.getStackTrace()[i];
              sw.append( separator ).append( element.toString() );
          }
          return sw.toString();
      }