[delete.tentative.html]
  [execCommand("delete", false, ""): "a    [\]||    c"]
    expected: FAIL

  [execCommand("delete", false, ""): "a    |[\]|    c"]
    expected: FAIL

  [execCommand("delete", false, ""): "a    || [\]   c"]
    expected: FAIL

  [execCommand("delete", false, ""): "a    ||[\]    c"]
    expected: FAIL

  [execCommand("delete", false, ""): "<span>abc&nbsp;</span><span>&nbsp; [\]def</span>"]
    expected: FAIL