extern const char* const kXlaCompileTimeConstantInputsAttr;

using OrderedNodeSet = std::set<Node*, NodeComparatorID>;

// Returns true if `node` has a ref tensor input that it forwards to its output.
bool HasForwardedRefInput(const Node& node);

// Creates a graph representation to enable cycle detection when clustering.
// This representation handles loops in graph by disconnecting each loop from
// the enclosing graph.
//

    absl::StrAppend(&description, ascii_art, node_name(node_id), "\n");
  }
  return description;
}

bool AlwaysForwardsRefInput(const Node& node) { return node.IsIdentity(); }

}  // namespace

bool HasForwardedRefInput(const Node& node) {
  if (AlwaysForwardsRefInput(node)) {
    for (const Edge* incoming_edge : node.in_edges()) {
      if (incoming_edge->IsControlEdge()) {
        continue;
      }

  }

  // XLA does not offer guaranteed aliasing between the input and output of the
  // XLA cluster so it can't implement the forward-tensor-ref semantic.  Leave
  // such nodes out of XLA clusters.
  if (HasForwardedRefInput(node)) {
    VLOG(2) << "Rejecting " << node.name() << ": Identity with unsafe cast.";
    *uncompilable_reason = "Identity with unsafe cast.";
    return false;
  }