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
const promises = [];
    this.fontCache.forEach(function (promise) {
      promises.push(promise);
    });
    return Promise.all(promises).then(translatedFonts => {
      for (const translatedFont of translatedFonts) {
        if (translatedFont.loadedName === id) {
          translatedFont.fallback(handler);
          return;
        }
      }
    });
  }
  cleanup(manuallyTriggered = false) {