std::vector<tensorflow::Output> x_arg = OutputsFromTFOutputs(x, nx);
  std::vector<tensorflow::Output> dy_arg;

  {
    // We need to hold on to the lock while we have a scope that uses TF_Graph.
    mutex_lock graph_lock(g->mu);

    const int first_new_node_id = g->graph.num_node_ids();

    string prefix_cmp;
    const char* child_scope_name;
    if (prefix == nullptr) {

  // Set to true whenever a TensorHandle is copied onto the device
  bool* arrived_flag;
  // Set to true whenever an operation is executed
  bool* executed_flag;
  // If true, only explicit op placements are accepted. If false, uses
  // type-based dispatch.
  bool strict_scope_placement;
};

struct LoggedTensor {
  TFE_TensorHandle* tensor;
  LoggedTensor() = delete;
  explicit LoggedTensor(TFE_TensorHandle* tensor) : tensor(tensor) {}

#include <memory>

#include "tensorflow/c/experimental/filesystem/plugins/posix/copy_file.h"

namespace tf_posix_filesystem {

// Transfers up to `size` bytes from `dst_fd` to `src_fd`.
//
// This method uses a temporary buffer to hold contents.
int CopyFileContents(int dst_fd, int src_fd, off_t size) {
  // Use a copy buffer of 128KB but don't store it on the stack.
  constexpr static size_t kPosixCopyFileBufferSize = 128 * 1024;

#include <sys/sendfile.h>

#include "tensorflow/c/experimental/filesystem/plugins/posix/copy_file.h"

namespace tf_posix_filesystem {

// Transfers up to `size` bytes from `dst_fd` to `src_fd`.
//
// This method uses `sendfile` specific to linux after 2.6.33.
int CopyFileContents(int dst_fd, int src_fd, off_t size) {
  off_t offset = 0;
  int bytes_transferred = 0;
  int rc = 1;

  return OkStatus();
}

// Checks if the plugin and core ABI numbers match, for all operations.
//
// If the numbers don't match, plugin cannot be loaded.
//
// Uses the simpler `CheckABI(int, int, StringPiece)`.
static Status ValidateABI(const TF_FilesystemPluginOps* ops) {
  TF_RETURN_IF_ERROR(
      CheckABI(ops->filesystem_ops_abi, TF_FILESYSTEM_OPS_ABI, "filesystem"));

  }

 private:
  TFE_Context* context_;
  TFE_CustomDevice device_;
  void* info_;
  string name_;
};

// An adapter which wraps the shape/data produced by C custom devices and uses
// it to implement custom device methods.
class CAPICustomDeviceTensorHandle
    : public tensorflow::CustomDeviceTensorHandle {
 public:
  CAPICustomDeviceTensorHandle(tensorflow::ImmediateExecutionContext* context,