code: public ListInstanceGroupsResult withInstanceGroups(InstanceGroup... instanceGroups) {
          if (this.instanceGroups == null) {
              setInstanceGroups(new com.amazonaws.internal.SdkInternalList<InstanceGroup>(instanceGroups.length));
          }
          for (InstanceGroup ele : instanceGroups) {
              this.instanceGroups.add(ele);
          }
          return this;
      }
docs: <p>
  The list of instance groups for the cluster and given filters.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setInstanceGroups(java.util.Collection)} or {@link #withInstanceGroups(java.util.Collection)} if you want
  to override the existing values.
  </p>
  
  @param instanceGroups
  The list of instance groups for the cluster and given filters.
  @return Returns a reference to this object so that method calls can be chained together.