I need to add another state to a function in account/static/src/js/ tax_group.js line 94

var displayEditWidget = self._isPurchaseDocument() && this.record.data.state === 'draft' && this.getParent().mode === 'edit';

I already added inheritance to web.assets_backend but don't know how to exactly overwrite the function.

I hope somebody can help me. 

Thank you very much

Paul