// Construct a local filesystem dataset repository rooted at /tmp/hello-cdk
DatasetRepository repo = DatasetRepositories.open("repo:file:/tmp/hello-cdk");
// Create a dataset of Hellos
DatasetDescriptor descriptor = new DatasetDescriptor.Builder()
.schema(Hello.class).build();
Dataset<Hello> hellos = repo.create("hellos", descriptor);
// Write some Hellos in to the dataset
DatasetWriter<Hello> writer = hellos.newWriter();