EDIT

 *

 * @return array of footnote keys

 */

  $foot_note_keys = [];

  foreach ($cdm_entities as $cdm_entity) {

 *   The foot note keys

 *

 * @throws \Exception re-throw exception from theme()

 *    For original sources the $footnote_list_key_suggestion will be overwritten by bibliography_footnote_list_key() when

 *    $is_bibliography_aware is set TRUE.

 * @$original_source_footnote_tag

 *

 * @throws \Exception

 *

 */

  function handle_annotations_and_sources($entity, $config, $inline_text_prefix, $footnote_list_key_suggestion) {

  $out = '';

  if(is_array($cdm_entities)){

    // array of entities

  } else {

    // single entity

    $footNoteKeys = cdm_entity_annotations_as_footnotekeys($cdm_entities, $footnote_list_key);