/**
 * log where in the code you are, class/method/line
 */
static void imAt( PrintWriter log )
   {
   Throwable t = new Throwable();
   StackTraceElement[] es = t.getStackTrace();
   StackTraceElement e = es[1];
   log.println( "at " + e.getClassName()
                + "."+ e.getMethodName()
                + " line:" + e.getLineNumber() );
   }