code: def filter_last_write(client, groups, start):
      
      retry = get_retry(('ThrottlingException',))
  
      def process_group(group_set):
          matched = []
          for g in group_set:
              streams = retry(
                  client.describe_log_streams,
                  logGroupName=g['logGroupName'],
                  orderBy='LastEventTime',
                  limit=1, descending=True)
              if not streams.get('logStreams'):
                  continue
              stream = streams['logStreams'][0]
              if stream['storedBytes'] == 0 and datetime.fromtimestamp(
                      stream['creationTime'] / 1000) > start:
                  matched.append(g)
              elif 'lastIngestionTime' in stream and datetime.fromtimestamp(
                      stream['lastIngestionTime'] / 1000) > start:
                  matched.append(g)
          return matched
  
      results = []
  
      with ThreadPoolExecutor(max_workers=3) as w:
          futures = {}
          for group_set in chunks(groups, 10):
              futures[w.submit(process_group, group_set)] = group_set
  
          for f in as_completed(futures):
              if f.exception():
                  log.error(
                      "Error processing groupset:%s error:%s",
                      group_set,
                      f.exception())
              results.extend(f.result())
  
      return results
docs: Filter log groups where the last write was before the start date.