//
// If async execution is enabled, the call may simply enqueue the execution
// and return "non-ready" handles in `retvals`. Note that any handles contained
// in 'op' should not be mutated till the kernel execution actually finishes.
//
// For sync execution, if any of the inputs to `op` are not ready, this call
// will block till they become ready and then return when the kernel execution
// is done.

// On success, enqueues `tensor` into a TF-managed FifoQueue given by
// `tensor_id`, associated with `session`. There must be a graph node named
// "fifo_queue_enqueue_<tensor_id>", to be executed by this API call. It reads
// from a placeholder node "arg_tensor_enqueue_<tensor_id>".
//
// `tensor` is still owned by the caller. This call will be blocked if the queue
// has reached its capacity, and will be unblocked when the queued tensors again

      pruning_thread_.reset();
    }
  }

  /// Read `n` bytes from `filename` starting at `offset` into `buffer`. It
  /// returns total bytes read ( -1 in case of errors ). This method will set
  /// `status` to:
  ///
  /// 1) The error from the remote filesystem, if the read from the remote
  ///    filesystem failed.
  /// 2) `TF_FAILED_PRECONDITION` if the read from the remote filesystem
  /// succeeded,