As I work I use folding to "hide" functions that I'm not working on.
Saving the project and reload it later does not save also the functions that I have fold, so I need to do the job again.
I believe that it will quite nice to have this feature.
You may also use custom folding marks:
// <editor-fold defaultstate="collapsed">
to collapse a portion of code as a workaround
*** This bug has been marked as a duplicate of bug 188573 ***