code: public GoogleEntry updateEntry(GoogleEntry entry) throws IOException {
          GoogleCalendar calendar = (GoogleCalendar) entry.getCalendar();
          Event event = converter.convert(entry, Event.class);
          dao.events().update(calendar.getId(), event.getId(), event).execute();
          return entry;
      }
docs: Performs an immediate update operation on google server by sending the
  information stored by the given google entry.
  
  @param entry The entry to be updated in a backend google calendar.
  @return The same instance received.
  @throws IOException For unexpected errors