Hide close button

Here is a little tip about how to hide the close button in the tabs.
As you can read here the sentences are:

System.setProperty("netbeans.tab.close.button.enabled","false");
System.setProperty("nb.tabs.suppressCloseButton","true");

but I put it the 'restored()' method of my ModuleInstall class and it works fine.

Here you can find a more extensive list of options.