The spec for this action:
https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/PDF32000_2008.pdf#G11.2111850
An example of a form using this action:
https://www2.illinois.gov/rev/forms/reg/Documents/reg-1-mr.pdf
return (
      nWidget >= 0 &&
      nWidget < this._radioIds.length &&
      this._id === this._radioIds[nWidget]
    );
  }
  isDefaultChecked(nWidget) {
    return (
      nWidget >= 0 &&
      nWidget < this.exportValues.length &&
      this.defaultValue === this.exportValues[nWidget]
    );
  }
  _getExportValue(state) {
    const i = this._radioIds.indexOf(this._id);
    return this.exportValues[i];
  }
  _runActions(event) {
    const i = this._radioIds.indexOf(this._id);
    this._actions = this._radioActions[i];
    return super._runActions(event);
  }
  _isButton() {
    return true;
  }
}
class CheckboxField extends RadioButtonField {