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;
    }

#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;

         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.

    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_);

}

// 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);