This should show, even though it is inside shadow DOM.
Popover 1
Hiding this popover will hide *all* open popovers,
because t2b2 doesn't exist in this context.
This popover will stay open when popover2 shows.
This should not get hidden when popover2 opens.
This should not hide popover1.
This should not get hidden when popover2 opens.
This should not hide popover1.