code: @InternalApi
    com.google.bigtable.admin.v2.Cluster toEmbeddedProto(String projectId) {
      proto.getClusterBuilder().setLocation(NameUtil.formatLocationName(projectId, zone));
  
      return proto.getClusterBuilder().build();
    }
docs: Creates the request protobuf to be used in {@link CreateInstanceRequest}. This method is
  considered an internal implementation detail and not meant to be used by applications.
  
  <p>This method is considered an internal implementation detail and not meant to be used by
  applications.