This is a test to make sure SessionStorage mutations fire StorageEvents that are caught by the event listener corresponding to body.onstorage. The event listener is setup via body.setAttribute().
Storage event fired:
Key - FOO
New Value - BAR
Old Value - null

Storage event fired:
Key - FU
New Value - BAR
Old Value - null

Storage event fired:
Key - FOO
New Value - null
Old Value - BAR

Storage event fired:
Key - FU
New Value - null
Old Value - BAR


