SetLabel doesn't work on a JPopupMenu

Question

For me the setLabel method of the java's JPopupMenu does not work.

Here is a simple popup menu example:

http://www.java2s.com/Code/Java/Swing-JFC/AsimpleexampleofJPopupMenu.htm

Inside is:

public JPopupMenu popup;
popup = new JPopupMenu();
popup.setLabel("Justification");

But when I launch the script, my popup menu has no label "Justification":

However, the documentation says this is the right way to define labels:

public void setLabel(String label)

http://docs.oracle.com/javase/7/docs/api/javax/swing/JPopupMenu.html#setLabel%28java.lang.String%29

I am using Eclipse 3.7.2, with JRE 1.7_067.

Of course, the same problem occurs on my own project...

Any help would be greatly appreciated!

Regards,