@atlaskit/adf-schema/dist/es2019/schema/marks/unsupported-node-attributes.js

Shared package that contains the ADF-schema (json) and ProseMirror node/mark specs

import { unsupportedNodeAttribute as unsupportedNodeAttributeFactory } from '../../next-schema/generated/markTypes';
export const unsupportedNodeAttribute = unsupportedNodeAttributeFactory({
  toDOM() {
    return ['span'];
  }
});