code: @Programmatic
      public List<String> choices(final Object taggedObject, final String tagKey) {
          final Bookmark bookmark = bookmarkService.bookmarkFor(taggedObject);
          final String objectType = bookmark.getObjectType();
  
          final Query q = isisJdoSupport.getJdoPersistenceManager().newNamedQuery(Tag.class, "findValuesByObjectTypeAndKey");
          final List<String> results = (List<String>) q.execute(objectType, tagKey);
          return results;
      }
docs: Returns the list of available values for a particular Tag key for other entities of the same
  {@link org.apache.isis.applib.services.bookmark.Bookmark#getObjectType() object type} as the provided object.
  
  <p>
  For example, an object with a <i>Sector</i> tag could use the following to determine the Sector
  values used by other objects of the same type:
  
  <pre>
  public List<String> choicesSector() {
  return tags.choices(this, "Sector");
  }
  </pre>