code: @SuppressWarnings("WeakerAccess")
    public ApiFuture<Void> deleteClusterAsync(String instanceId, String clusterId) {
      String name = NameUtil.formatClusterName(projectId, instanceId, clusterId);
  
      com.google.bigtable.admin.v2.DeleteClusterRequest request =
          com.google.bigtable.admin.v2.DeleteClusterRequest.newBuilder()
              .setName(name.toString())
              .build();
  
      return ApiFutures.transform(
          stub.deleteClusterCallable().futureCall(request),
          new ApiFunction<Empty, Void>() {
            @Override
            public Void apply(Empty input) {
              return null;
            }
          },
          MoreExecutors.directExecutor());
    }
docs: Asynchronously deletes the specified cluster. Please note that an instance must have at least 1
  cluster. To remove the last cluster, please use {@link
  BigtableInstanceAdminClient#deleteInstanceAsync(String)}.
  
  <p>Sample code:
  
  <pre>{@code
  ApiFuture<Void> future = client.deleteClusterAsync("my-instance", "my-cluster");
  future.get();
  }</pre>