public:
  ReproducerStream(std::string name, std::unique_ptr<llvm::raw_ostream> os)
      : name_(std::move(name)), os_(std::move(os)) {}

  llvm::StringRef description() override { return name_; }

  llvm::raw_ostream& os() override { return *os_; }

 private:
  std::string name_;
  std::unique_ptr<llvm::raw_ostream> os_;
};

// Returns a function that builds a reproducer stream, or nullptr if the MLIR