docs: public DBEngineVersion withValidUpgradeTarget(UpgradeTarget... validUpgradeTarget) {
          if (this.validUpgradeTarget == null) {
              setValidUpgradeTarget(new com.amazonaws.internal.SdkInternalList<UpgradeTarget>(validUpgradeTarget.length));
          }
          for (UpgradeTarget ele : validUpgradeTarget) {
              this.validUpgradeTarget.add(ele);
          }
          return this;
      }