code: public DescribeHostReservationOfferingsResult withOfferingSet(HostOffering... offeringSet) {
          if (this.offeringSet == null) {
              setOfferingSet(new com.amazonaws.internal.SdkInternalList<HostOffering>(offeringSet.length));
          }
          for (HostOffering ele : offeringSet) {
              this.offeringSet.add(ele);
          }
          return this;
      }
docs: <p>
  Information about the offerings.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setOfferingSet(java.util.Collection)} or {@link #withOfferingSet(java.util.Collection)} if you want to
  override the existing values.
  </p>
  
  @param offeringSet
  Information about the offerings.
  @return Returns a reference to this object so that method calls can be chained together.