docs: @BetaApi
    public final Operation insertBackendBucket(String project, BackendBucket backendBucketResource) {
  
      InsertBackendBucketHttpRequest request =
          InsertBackendBucketHttpRequest.newBuilder()
              .setProject(project)
              .setBackendBucketResource(backendBucketResource)
              .build();
      return insertBackendBucket(request);
    }