// Returns the list of nodes in the graph. Nodes are presented in the reverse
  // order of a post-order depth-first visit starting from the graph's source
  // nodes.
  llvm::ArrayRef<Node*> GetOrderedNodes() const { return ordered_nodes_; }

  // Returns the inferred input type at index `idx` of the `node` in the
  // context.
  absl::StatusOr<mlir::Type> InferInputType(const Node& node, int idx,