}
  }
}

// Build a `tf_device.launch` op with a region that contains all the operations
// in given cluster. Then all ops in cluster are replaced by `tf_device.launch`.
void BuildLaunchForCluster(const TF::Cluster& c, OpBuilder* builder) {
  // Set insertion point to right after all operations in cluster.
  builder->setInsertionPoint(c.ops.back()->getNextNode());