class ConvertLSTMCellSimpleToFusedLSTM {
 public:
  explicit ConvertLSTMCellSimpleToFusedLSTM(mlir::func::FuncOp fused_func_op)
      : fused_func_op_(fused_func_op),
        couple_input_forget_gates_(false),
        builder_(fused_func_op.getBody()) {}

  // not copyable.
  ConvertLSTMCellSimpleToFusedLSTM(const ConvertLSTMCellSimpleToFusedLSTM&) =
      delete;