code: @SuppressWarnings("WeakerAccess")
    public ApiFuture<Void> deleteInstanceAsync(String instanceId) {
      String instanceName = NameUtil.formatInstanceName(projectId, instanceId);
  
      com.google.bigtable.admin.v2.DeleteInstanceRequest request =
          com.google.bigtable.admin.v2.DeleteInstanceRequest.newBuilder()
              .setName(instanceName)
              .build();
  
      return ApiFutures.transform(
          stub.deleteInstanceCallable().futureCall(request),
          new ApiFunction<Empty, Void>() {
            @Override
            public Void apply(Empty input) {
              return null;
            }
          },
          MoreExecutors.directExecutor());
    }
docs: Asynchronously deletes the specified instance.
  
  <p>Sample code:
  
  <pre>{@code
  ApiFuture<Void> deleteFuture = client.deleteInstanceAsync("my-instance");
  deleteFuture.get();
  }</pre>