code: def fetch_sampling_rules(self):
          
          new_rules = []
  
          resp = self._xray_client.get_sampling_rules()
          records = resp['SamplingRuleRecords']
  
          for record in records:
              rule_def = record['SamplingRule']
              if self._is_rule_valid(rule_def):
                  rule = SamplingRule(name=rule_def['RuleName'],
                                      priority=rule_def['Priority'],
                                      rate=rule_def['FixedRate'],
                                      reservoir_size=rule_def['ReservoirSize'],
                                      host=rule_def['Host'],
                                      service=rule_def['ServiceName'],
                                      method=rule_def['HTTPMethod'],
                                      path=rule_def['URLPath'],
                                      service_type=rule_def['ServiceType'])
                  new_rules.append(rule)
  
          return new_rules
docs: Use X-Ray botocore client to get the centralized sampling rules
          from X-Ray service. The call is proxied and signed by X-Ray Daemon.