docs: public DescribeReservedInstancesResult withReservedInstances(ReservedInstances... reservedInstances) {
          if (this.reservedInstances == null) {
              setReservedInstances(new com.amazonaws.internal.SdkInternalList<ReservedInstances>(reservedInstances.length));
          }
          for (ReservedInstances ele : reservedInstances) {
              this.reservedInstances.add(ele);
          }
          return this;
      }