docs: public DescribeDBSubnetGroupsResult withDBSubnetGroups(DBSubnetGroup... dBSubnetGroups) {
          if (this.dBSubnetGroups == null) {
              setDBSubnetGroups(new com.amazonaws.internal.SdkInternalList<DBSubnetGroup>(dBSubnetGroups.length));
          }
          for (DBSubnetGroup ele : dBSubnetGroups) {
              this.dBSubnetGroups.add(ele);
          }
          return this;
      }