// that this test will run on Windows since `tensorflow::io::JoinPath`
      // behaves differently on Windows. `tmp_dir` should be something like
      // `path/to/tmp/dir/`. After joining path, we will have
      // /path/to/tmp/dir/tf_fs_rng_name/`
      root_dir_ = tensorflow::strings::StrCat(
          "/", tmp_dir_,
          tensorflow::strings::StrCat("tf_fs_", rng_val_, "_", test_name), "/");

 private:
  struct Entry {
    /// The timestamp (seconds) at which the entry was added to the cache.
    uint64_t timestamp;

    /// The entry's value.
    T value;

    /// A list iterator pointing to the entry's position in the LRU list.
    std::list<std::string>::iterator lru_iterator;
  };

  bool LookupLocked(const std::string& key, T* value)
      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {

The top-level scripts and utility scripts should be fairly well-documented. Here
is a brief explanation of how they tie together:

1.  `envs/*` are lists of variables made with bash syntax. A user must set a
    `TFCI` env param pointing to a list of `env` files.
2.  `utilities/setup.sh`, initialized by all top-level scripts, reads and sets
    values from those `TFCI` paths.
    -   `set -a` / `set -o allexport` exports the variables from `env` files so

  /// mu_.
  struct Block {
    /// The block data.
    std::vector<char> data;
    /// A list iterator pointing to the block's position in the LRU list.
    std::list<Key>::iterator lru_iterator;
    /// A list iterator pointing to the block's position in the LRA list.
    std::list<Key>::iterator lra_iterator;
    /// The timestamp (seconds since epoch) at which the block was cached.

TF_CAPI_EXPORT extern void TF_DeleteVariableInfo(TF_VariableInfo* var_info);

// ---------------------  Coordination service  --------------------------------
// Returns a not owning pointer to the coordination service agent, which is
// opaque to plugin. Plugin OpKernels need to use the accompanying C APIs to
// access coordination service functionalities.
TF_CAPI_EXPORT extern TF_CoordinationServiceAgent*

        mode. In this mode, the table resource can only be accessed via resource
        handles (not resource names) and will be deleted automatically when all
        resource handles pointing to it are gone.
*   `tf.data`:
    *   Introduce the `tf.data.experimental.at` API which provides random access
        for input pipelines that consist of transformations that support random

  // AssignSub, ...).
  void GeneralAssignment(const char* op_name, TFE_Context* context,
                         TFE_TensorHandle* value, TF_Status* status);

  // The a handle for the resource-dtype tensor pointing to the variable's
  // buffer.
  TFE_TensorHandle* handle_;
  // The dtype of the variable's buffer (input dtype for assignments, output
  // dtype of read operations).
  TF_DataType type_;
};

    TF_OperationDescription* desc, TF_Status* status);

// If this function succeeds:
//   * *status is set to an OK value,
//   * a TF_Operation is added to the graph,
//   * a non-null value pointing to the added operation is returned --
//     this value is valid until the underlying graph is deleted.
// Otherwise:
//   * *status is set to a non-OK value,
//   * the graph is not modified,