[clamping-001.tentative.html]
  [1. opacity keyframes should not clamp before compositing, replace -1 + add 1 = 0]
    expected: FAIL
  [2. opacity keyframes should not clamp before compositing, replace 1 + add -1 = 0]
    expected: FAIL
  [3. opacity keyframes should not clamp before compositing, replace -2 + add 2 = 0]
    expected: FAIL
  [4. opacity keyframes should not clamp before compositing, replace 2 + add -2 = 0]
    expected: FAIL
  [7. opacity keyframes should not clamp before compositing, replace -100% + add 100% = 0]
    expected: FAIL
  [8. opacity keyframes should not clamp before compositing, replace 100% + add -100% = 0]
    expected: FAIL
  [9. opacity keyframes should not clamp before compositing, replace -200% + add 200% = 0]
    expected: FAIL
  [10. opacity keyframes should not clamp before compositing, replace 200% + add -200% = 0]
    expected: FAIL