Allow format in parent container (ContainerBlot)

[8lurry]

I want to have user inserted className on table, tr, and td tags. Below is an example code for inserting className on tr tag.
I have the following changes in TableRow

const QuillTableRow = Quill.import("formats/table-row");

class TableRow extends QuillTableRow {
    static create(value) {
        const node = super.create();
        if (value) node.setAttribute("class", value);
        return node;
    }

    static formats(domNode, scroll) {
        if (domNode.hasAttribute("class")) {
            return domNode.getAttribute("class")
        }
        return undefined;
    }

    formats() {
        return TableRow.formats(this.domNode);
    }

    format(name, value) {
        if (name === TableRow.blotName && value) {
            this.domNode.setAttribute('class', value);
        } else {
            super.format(name, value);
        }
    }
}

Quill.register(TableRow);

Shouldn't this implementation be respected?

Given a row (by selection) gotten from quill.getModule("table").getTable() when I call formatLine:

const index = quill.getIndex(row);
quill.formatLine(index, 1, TableRow.blotName, classes);

the format is NOT applied (as in the className is not preserved in tr tag) and the cell in selection disappears (gets deleted).
Also when I try to insert html containing a row format by doing the following:

const value = (
`<table>
    <tbody>
        <tr class="dangling-modification">
            <td data-row="row-t9q9">foo</td>
            <td data-row="row-t9q9">bar</td>
        </tr>
        <tr>
            <td data-row="row-xgef"><br/></td>
            <td data-row="row-xgef"><br/></td>
        </tr>
    </tbody>
</table>`);
quill.clipboard.dangerouslyPasteHTML(value);

a cell still disappears.
Is there some other ways of doing this?
Or any other suggestions?
TIA