This is a test to make sure you can get and set values in SessionStorage by index.
Setting FOO using the index setter.
Storage event fired:
Key - FOO
New Value - BAR
Old Value - null

Reading FOO:
BAR
BAR
BAR

Setting FOO again, using setItem.
Storage event fired:
Key - FOO
New Value - BAZ
Old Value - BAR

Reading FOO:
BAZ
BAZ
BAZ

Setting FOO again, using the index setter.
Storage event fired:
Key - FOO
New Value - BAT
Old Value - BAZ

Reading FOO:
BAT
BAT
BAT

Setting FOO again, using property-slot syntax
Storage event fired:
Key - FOO
New Value - BATMAN
Old Value - BAT

Reading FOO:
BATMAN
BATMAN
BATMAN

Removing FOO, then trying to read it
Storage event fired:
Key - FOO
New Value - null
Old Value - BATMAN

Reading FOO:
undefined
undefined
null


