if (pjrt_tensor_buffer != nullptr) {
        args->push_back(pjrt_tensor_buffer->pjrt_buffer());
      } else {
        // Creates a PjRtBuffer from DeviceMemoryBase. The newly created
        // PjRtBuffer needs to be persisted till XLA execution is completed.
        auto dmem = se::DeviceMemoryBase(
            const_cast<char*>(tensor->tensor_data().data()),

  auto new_launch_op = builder.create<tf_device::LaunchOp>(
      old_launch_op->getLoc(), old_launch_op->getDeviceAttr(),
      /*result_types=*/new_launch_op_results_types);

  new_launch_op.getBody().takeBody(old_launch_op->getBody());
  new_launch_op.GetBody().getTerminator()->setOperands(new_launch_op_results);

  return new_launch_op;
}

// Create the new device launch op which wraps the copy op.

                                                new_results)))
      return failure();

    // Update the regions. The dialect conversion framework wants new regions to
    // be created and updated, rather than updating the old op. Thus we use an
    // OperationState so we can add regions to the new op.
    OperationState state(op->getLoc(), op->getName().getStringRef(), operands,

      OpBuilder replacer(yield_op);
      island_op.getBody().push_back(new Block);
      replacer.create<mlir::func::ReturnOp>(yield_op.getLoc(),
                                            yield_op.getOperands());
      yield_op.erase();
    }

    // Remap the captured operands in the (former) island block with newly
    // created entry block arguments in the function body.
    {

}

// Wraps block in a Launch. External uses of ops in the block will be return
// values of the Launch and remapped to the Launch results. If `before` is set
// to true, the Launch is created before `op`. Otherwise the Launch is created
// after `op`.
mlir::tf_device::LaunchOp CreateLaunchForBlock(OpBuilder* builder,
                                               Operation* op, bool before,

                 Out(NodeWith(
                     Op("Slice"),
                     Name("begin/static_shaped_slice/static_shaped_slice"))),
                 _)));
}

// New constants being created need to have control dependencies copied to
// ensure correct control flow analysis in TF V2.
TEST(SliceToDynamicSliceRewriteTest, WithControlDepsToConstant) {
  Scope root = Scope::NewRootScope()

      tensorflow::GetTypeFromTFTensorShape({1}, shape_dtype);
  auto expanded_start_index = rewriter->create<TF::ExpandDimsOp>(
      loc, vector_type, start_index, scalar_zero);
  auto start_position = rewriter->create<TF::ConcatOp>(
      loc, position_type, scalar_zero,
      ArrayRef<Value>({expanded_start_index, partial_start_position}));

  // Create the slice size tensor. This is done by concatenating `size` and
  // `partial_size`.

  void MarkAsResult(AbstractTensorHandle* gradient) const override;

  void DeleteGradient(AbstractTensorHandle* gradient) const override;

 private:
  // The context where the aggregation op `Add` is to be created.
  AbstractContext* ctx_;
};

// Returns the number of elements in the gradient tensor.
int64_t TapeVSpace::NumElements(AbstractTensorHandle* tensor) const {

  }
  void runOnOperation() override;
};

// Creates a call to function `func` in region `caller_region`. Use `args` as
// the call arguments, and terminate the region with a yield. The arguments are
// cast to the required type before the call. `use_region_args` control whether
// the input arguments are used as is (for IfOp) or block arguments of the same
// type as the input arguments are created and then used as call arguments (for
// While).

      builder.clone(*op, mapping);
    }
    // Creates the ReturnOp so that the per-host function returns the
    // correct values of the cloned operations.
    llvm::SmallVector<Value, 4> results_after_mapping;
    for (Value result : metadata.results) {
      results_after_mapping.push_back(mapping.lookupOrDefault(result));
    }
    builder.create<func::ReturnOp>(loc, results_after_mapping);