char* p = static_cast<char*>(storage);
  for (int i = 0; i < len; ++i) {
    const string& s = attr->list().s(i);
    values[i] = p;
    lengths[i] = s.size();
    if ((p + s.size()) > (static_cast<char*>(storage) + storage_size)) {
      status->status = InvalidArgument(
          "Not enough storage to hold the requested list of strings");
      return;
    }

                                   size_t* storage_size, TF_Status* status) {
  TF_SetStatus(status, TF_OK, "");
  const std::unordered_set<std::string>& nodes =
      reinterpret_cast<const tensorflow::grappler::GrapplerItem*>(item)
          ->NodesToPreserve();
  *num_values = nodes.size();
  *storage_size = 0;
  for (const std::string& str : nodes) {
    *storage_size += str.size();
  }
}

    std::vector<size_t> lens(expected.size());
    std::unique_ptr<char[]> storage(new char[m.total_size]);
    TF_OperationGetAttrStringList(op, tensorflow::kColocationAttrName,
                                  values.data(), lens.data(), expected.size(),
                                  storage.get(), m.total_size, s_);
    EXPECT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

  std::unique_ptr<size_t[]> lens(new size_t[nodes_preserved.size()]);
  std::unique_ptr<char[]> storage(new char[storage_size]);
  TF_GetNodesToPreserveList(c_item, values.get(), lens.get(),
                            nodes_preserved.size(), storage.get(), storage_size,
                            status);
  EXPECT_EQ(TF_OK, TF_GetCode(status)) << TF_Message(status);

  for (size_t i = 0; i < nodes_preserved.size(); ++i) {

// 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;
  std::unique_ptr<char[]> buffer(new char[kPosixCopyFileBufferSize]);

  off_t offset = 0;
  int bytes_transferred = 0;
  int rc = 1;

}

// Tests whether a URI scheme results in a filesystem that is supported.
//
// As we need these URI schemes to instantiate the test suite when
// `testing::InitGoogleTest` gets called, here we just store them to an
// internal scheme registry. See `URISchemeRegister` above.
static bool GetURIScheme(const std::string& scheme) {
  tensorflow::SchemeVector()->push_back(scheme);
  return true;
}

    EXPECT_EQ(TF_OK, TF_GetCode(status)) << TF_Message(status);
    TFE_DeleteTensorHandle(n);
    n = n_gpu;
  }

  TFE_TensorHandle* m = TestMatrixTensorHandle100x100(ctx);

  // Store pointer to raw buffer for validation of forwarding behaviour.
  TF_Tensor* orig = TFE_TensorHandleResolve(n, status);
  void* orig_ptr = TF_TensorData(orig);
  TF_DeleteTensor(orig);

  TFE_Op* add_op = AddOp(ctx, n, m);

#include "absl/types/variant.h"
#include "google/cloud/storage/client.h"
#include "tensorflow/c/env.h"
#include "tensorflow/c/experimental/filesystem/plugins/gcs/gcs_helper.h"
#include "tensorflow/c/logging.h"
#include "tensorflow/c/tf_status.h"

// Implementation of a filesystem for GCS environments.
// This filesystem will support `gs://` URI schemes.
namespace gcs = google::cloud::storage;

static const char* content = "abcdefghijklmnopqrstuvwxyz1234567890";
// We will work with content_view instead of content.
static const absl::string_view content_view = content;

namespace gcs = google::cloud::storage;

static std::string InitializeTmpDir() {
  // This env should be something like `gs://bucket/path`
  const char* test_dir = getenv("GCS_TEST_TMPDIR");
  if (test_dir != nullptr) {
    std::string bucket, object;

         TF_TensorByteSize(theta_tensor));

  // Initialize space for the numerical gradient.
  vector<float> dtheta_approx(num_elems);

  // Get theta shape and store in theta_dims.
  int num_dims = TF_NumDims(theta_tensor);
  vector<int64_t> theta_dims(num_dims);
  GetDims(theta_tensor, theta_dims.data());

  // Initialize auxilary data structures.