explicit RuntimeFallbackExecutor(int64_t num_threads);

  // Prepare() needs to be called once before calling Execute(). It sets up all
  // things necessary to execute the given 'mlir_input' with the fallback to
  // tensorflow.
  void Prepare(llvm::StringRef mlir_input);

  // Execute() can be called several times after the call to Prepare() (e.g. for
  // benchmarking).
  llvm::SmallVector<Tensor> Execute(llvm::StringRef function_name,

}

void RuntimeFallbackExecutor::Prepare(llvm::StringRef mlir_input) {
  // We only support IR written in the Tensorflow dialect.
  mlir::DialectRegistry registry;
  mlir::RegisterAllTensorFlowDialects(registry);
  mlir::MLIRContext context(registry);

  llvm::SourceMgr source_mgr;
  source_mgr.AddNewSourceBuffer(
      llvm::MemoryBuffer::getMemBuffer(mlir_input, "test_ir"), llvm::SMLoc());