if (!s.ok()) return s;

  Node* n = g->AddNode(key_def, &s);
  if (!s.ok()) return s;
  return n;
}

// Returns if the node is a XLA computation key placeholder.
bool IsKeyPlaceholderNode(const Node& n) {
  return n.type_string() == "Placeholder" &&
         absl::EndsWith(n.name(), "_key_placeholder");
}

// Returns nodes with given type.