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

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

export const unsupportedNodeAttribute = {
  toDOM() {
    return ['span'];
  },
  attrs: {
    type: {},
    unsupported: {}
  }
};