docs: public DescribeFolderContentsResult withFolders(FolderMetadata... folders) {
          if (this.folders == null) {
              setFolders(new java.util.ArrayList<FolderMetadata>(folders.length));
          }
          for (FolderMetadata ele : folders) {
              this.folders.add(ele);
          }
          return this;
      }