We have a bunch of these `table_attribs_n` tests already, but none capture this. The "class" is parsed as content because the pipe for attribute demarkation comes from the template.
```
{|
| class="hi" {{1x|{{!}}}} ho
|}
```
This is seen on https://ko.wikipedia.org/api/rest_v1/page/html/Maps_(%EB%A7%88%EB%A3%AC_5%EC%9D%98_%EB%85%B8%EB%9E%98)
```
{|
|-
!scope="row"{{singlechart|UK|2|date=2014-09-06}}
|}
```
Here is a perverse example. Effectively, the core parser generates the string for the line and then parses table cells and attributes, but it is too late for Parsoid with its tokenizer. Parsoid has a different rendering for the first 4 table rows because of this.
```
{|
|-
| abcd {{1x|{{!}}}} ho
|-
| style="border:1px solid red" {{1x|{{!}}}} ho
|-
| abcd |{{1x|{{!}}}} ho
|-
| style="border:1px solid red" |{{1x|{{!}}}} ho
|-
| abcd {{1x|{{!}}{{!}}}} ho
|-
| style="border:1px solid red" {{1x|{{!}}{{!}}}} ho
|}
```