docs: def lambda_handler(event, context):
      """Main handler."""
      table = boto3.resource("dynamodb").Table(os.environ['database'])
      results = table.scan()
      output = {'success': True, 'indicators': list(), 'indicatorCount': 0}
      for item in results.get('Items', list()):
          indicator = item.get('indicator', None)
          if not indicator:
              continue
          output['indicators'].append(indicator)
      output['indicators'] = list(set(output['indicators']))
      output['indicatorCount'] = len(output['indicators'])
      return output