Check that usage of the $popup filter option is working as expected.
With the filter displayed below each test case added to ABP (or with the testcase subscription installed and active), the popups triggered by the link/buttons below should be blocked/closed.
||testpages.adblockplus.org/en/popuptarget^$popup
||testpages.adblockplus.org/en/popuptarget^$popup
