docs: def get_rds_instances_by_region(self, region):
          ''' Makes an AWS API call to the list of RDS instances in a particular
          region '''
  
          try:
              conn = self.connect_to_aws(rds, region)
              if conn:
                  instances = conn.get_all_dbinstances()
                  for instance in instances:
                      self.add_rds_instance(instance, region)
          except boto.exception.BotoServerError as e:
              error = e.reason
  
              if e.error_code == 'AuthFailure':
                  error = self.get_auth_error_message()
              if not e.reason == "Forbidden":
                  error = "Looks like AWS RDS is down:\n%s" % e.message
              self.fail_with_error(error, 'getting RDS instances')