code: public DeleteFleetsResult withUnsuccessfulFleetDeletions(DeleteFleetErrorItem... unsuccessfulFleetDeletions) {
          if (this.unsuccessfulFleetDeletions == null) {
              setUnsuccessfulFleetDeletions(new com.amazonaws.internal.SdkInternalList<DeleteFleetErrorItem>(unsuccessfulFleetDeletions.length));
          }
          for (DeleteFleetErrorItem ele : unsuccessfulFleetDeletions) {
              this.unsuccessfulFleetDeletions.add(ele);
          }
          return this;
      }
docs: <p>
  Information about the EC2 Fleets that are not successfully deleted.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setUnsuccessfulFleetDeletions(java.util.Collection)} or
  {@link #withUnsuccessfulFleetDeletions(java.util.Collection)} if you want to override the existing values.
  </p>
  
  @param unsuccessfulFleetDeletions
  Information about the EC2 Fleets that are not successfully deleted.
  @return Returns a reference to this object so that method calls can be chained together.