// backends (graph/MLIR).
//
// This defines a set of abstract classes that are intended to provide the
// functionality of the opaque C types exposed in the public APIs defined in the
// `c_api_unified_experimental.h` header.
// =============================================================================

// Represents either a MlirTensor or a GraphTensor.

  AbstractTensorHandle* GetHandle() const;

 private:
  AbstractTensorHandle* handle_;
};

// A tracing/immediate-execution agnostic tape.
//
// Gradient functions defined for this tape must support handling null incoming
// gradients.
class Tape : protected eager::GradientTape<AbstractTensorHandle,
                                           GradientFunction, TapeTensor> {
 public:

namespace tensorflow {

// TODO(b/143949615): After all filesystems are converted, this file will be
// moved to core/platform, and this class can become a singleton and replace the
// need for `Env::Default()`. At that time, we might decide to remove the need
// for `Env::Default()` altogether, but that's a different project, not in
// scope for now. I'm just mentioning this here as that transition will mean

/// order to not have plugin shared objects call back symbols defined in core
/// TensorFlow, `TF_InitPlugin` has a `TF_FilesystemPluginInfo` argument which
/// the plugin must fill (using the `TF_SetFilesystemVersionMetadata` for the
/// metadata and setting up all the supported operations and the URI schemes
/// that are supported).

/// This structure incorporates the operations defined in Section 2 and the

  //===--------------------------------------------------------------------===//
  // Distributed runtime related functions.
  //===--------------------------------------------------------------------===//
#if !defined(IS_MOBILE_PLATFORM)
  // Set up a multi-client distributed execution environment. Must be called on
  // all tasks in the cluster.
  // This call internally coordinates with other tasks to initialize the eager