code: def _find_usage_cloudtrail(self):
          
  
          trail_list = self.conn.describe_trails()['trailList']
          trail_count = len(trail_list) if trail_list else 0
  
          for trail in trail_list:
              data_resource_count = 0
              if self.conn._client_config.region_name == trail['HomeRegion']:
                  response = self.conn.get_event_selectors(
                      TrailName=trail['Name']
                  )
                  event_selectors = response['EventSelectors']
                  for event_selector in event_selectors:
                      data_resource_count += len(
                          event_selector.get('DataResources', [])
                      )
                  self.limits['Event Selectors Per Trail']._add_current_usage(
                      len(event_selectors),
                      aws_type='AWS::CloudTrail::EventSelector',
                      resource_id=trail['Name']
                  )
                  self.limits['Data Resources Per Trail']._add_current_usage(
                      data_resource_count,
                      aws_type='AWS::CloudTrail::DataResource',
                      resource_id=trail['Name']
                  )
              else:
                  logger.debug(
                      'Ignoring event selectors and data resources for '
                      'CloudTrail %s in non-home region' % trail['Name']
                  )
          self.limits['Trails Per Region']._add_current_usage(
              trail_count,
              aws_type=self.aws_type
          )
docs: Calculate current usage for CloudTrail related metrics