// already have a cluster assigned to them (via `_replication_info`
        // attribute value).
        // `tf.Identity` op is also treated as special tpu ops since it can play
        // a role as connection between `tf.TPUReplicatedInput` or
        // `tf.TPUPartitionedInput`. For example, we have the follow pseudocode:
        // %0 = tf_executor.island wraps "tf.OpA" (){_replication_info = 'c'}

    "_cluster_outlined_function_name";
// Marks a node for replication. The attribute value indicates the replication
// metadata op.
inline constexpr llvm::StringRef kReplicationInfoAttr = "_replication_info";
// Marks a node for XLA-TPU compilation. The attribute value indicates the
// associated compilation cluster and replication metadata op.
inline constexpr llvm::StringRef kTpuReplicateAttr = "_tpu_replicate";

    ```

    wll be replaced by `_replication_info="cluster"` and  `_xla_compile_device_type="TPU"`.

    ```mlir

  "tf.ResourceApplyFtrl"(%var, %accum, %linear, %grad, %lr, %l1, %l2, %lr_power) {_xla_compile_device_type = "TPU", _replication_info = "cluster_train_function", device = "", multiply_linear_by_lr = false, use_locking = true} : (tensor<*x!tf_type.resource>, tensor<*x!tf_type.resource>, tensor<*x!tf_type.resource>, tensor<*xf32>, tensor<*xf32>, tensor<*xf32>, tensor<*xf32>,...

std::unique_ptr<OperationPass<func::FuncOp>>
CreateTPUPartitionedOpConversionPass();

std::unique_ptr<OperationPass<ModuleOp>> CreateTPUValidateInputsPass();

// Creates a pass that cleans up `_replication_info` attribute on operations
// that are inside a cluster.
std::unique_ptr<OperationPass<ModuleOp>>
CreateTPUClusterCleanupAttributesPass();

// Creates a pass that removes Identity/IdentityN ops from a cluster.