Keys used in this test include : Tab, Space, Enter, Left Arrow (LA), Right Arrow (RA).
1. Login as a student and tab through till the navigation block (add block in boost theme, if not available). Check that you can tab through every single branch node and leaf node.
2. Check that every non-link branch node toggle expansion on keys[Enter,Space] and check [RA] only expands and [LA] only collapses the branch.
3. Check that every link node toggles expansion on a [space] keypress but follows the link upon an [enter] keypress and check [RA] only expands and [LA] only collapses the branch.