[heading-pseudo-class-in-has-with-slot-reassignment.html]
  [Initial (h1 slotted into slot_a): #has_heading_3]
    expected: FAIL

  [h1.slot = 'b': #has_heading_5]
    expected: FAIL

  [h1.slot = 'nonexistent': #has_heading_1]
    expected: FAIL

  [h1.slot = 'a': #has_heading_3]
    expected: FAIL

  [slotA.name = 'c': #has_heading_1]
    expected: FAIL

  [slotB.name = 'a': #has_heading_5]
    expected: FAIL

  [Reset slot names: #has_heading_3]
    expected: FAIL

  [slotA.remove(): #has_heading_1]
    expected: FAIL

  [Re-insert slot_a: #has_heading_3]
    expected: FAIL