// the `Cast` will be preserved. This transform is needed for the graph to be
// executed on TPU or GPU devices, which do not have `Cast` registered as a
// runtime OpKernel.
void RemoveIdentityCast(NodeDef* node_def) {
  auto attr = node_def->mutable_attr();
  if (node_def->op() == "Cast" && attr->contains("SrcT") &&
      attr->contains("DstT") &&
      attr->at("SrcT").type() == attr->at("DstT").type() &&