docs: public ListClustersResult withClusters(ClusterSummary... clusters) {
          if (this.clusters == null) {
              setClusters(new com.amazonaws.internal.SdkInternalList<ClusterSummary>(clusters.length));
          }
          for (ClusterSummary ele : clusters) {
              this.clusters.add(ele);
          }
          return this;
      }