code: def _find_usage_plans(self):
          
          logger.debug('Finding usage for Usage Plans')
          plan_count = 0
          paginator = self.conn.get_paginator('get_usage_plans')
          for resp in paginator.paginate():
              plan_count += len(resp['items'])
          self.limits['Usage plans per account']._add_current_usage(
              plan_count, aws_type='AWS::ApiGateway::UsagePlan'
          )
docs: Find usage on Usage Plans and plans per API Key. Update `self.limits`.