   'togglePopover() should return true.');
  assert_true(popover.matches(':popover-open'),
    'togglePopover() should open the popover.');

  assert_true(popover.togglePopover(/*force=*/true),
    'togglePopover(true) should return true.');
  assert_true(popover.matches(':popover-open'),
    'togglePopover(true) should open the popover.');

  assert_false(popover.togglePopover(),
    'togglePopover() should return false.');
  assert_false(popover.matches(':popover-open'),
    'togglePopover() should close 