code: public Map<String, CSLItemData> toItemData(BibTeXDatabase db) {
  		Map<String, CSLItemData> result = new HashMap<>();
  		for (Map.Entry<Key, BibTeXEntry> e : db.getEntries().entrySet()) {
  			result.put(e.getKey().getValue(), toItemData(e.getValue()));
  		}
  		return result;
  	}
docs: Converts the given database to a map of CSL citation items
  @param db the database
  @return a map consisting of citation keys and citation items