code: public String getRawMasterDataSourceName(final String dataSourceName) {
          for (MasterSlaveRuleConfiguration each : shardingRuleConfig.getMasterSlaveRuleConfigs()) {
              if (each.getName().equals(dataSourceName)) {
                  return each.getMasterDataSourceName();
              }
          }
          return dataSourceName;
      }
docs: Get raw master data source name.
  
  @param dataSourceName data source name
  @return raw master data source name