/** Goes to source. */
 public void goToSource() {
   try {
     Line l = stackFrame.getLine();
     if (l != null) l.show(Line.SHOW_GOTO);
   } catch (DebuggerException e) {
   }
 }
 /** Returns true if source is availabled. */
 public boolean canGoToSource() {
   try {
     Line l = stackFrame.getLine();
     if (l != null) return true;
   } catch (DebuggerException e) {
   }
   return false;
 }