// nullptr will be returned.
TF_CAPI_EXPORT extern TF_Buffer* TF_CoordinationServiceGetKeyValue(
    const char* key, int64_t key_size, TF_CoordinationServiceAgent* agent,
    TF_Status* status);

TF_CAPI_EXPORT extern TF_Buffer* TF_CoordinationServiceGetKeyValueWithTimeout(
    const char* key, int64_t key_size, int64_t timeout_seconds,
    TF_CoordinationServiceAgent* agent, TF_Status* status);

                                                  TF_Status* status);
TF_CAPI_EXPORT extern int64_t TFE_TensorHandleNumElements(TFE_TensorHandle* h,
                                                          TF_Status* status);
// This function will block till the operation that produces `h` has completed.
TF_CAPI_EXPORT extern int64_t TFE_TensorHandleDim(TFE_TensorHandle* h,
                                                  int dim_index,

// and -1 will be returned.
TF_CAPI_EXPORT extern int64_t TF_DeviceListMemoryBytes(
    const TF_DeviceList* list, int index, TF_Status* status);

// Retrieve the incarnation number of a given device.
//
// If index is out of bounds, an error code will be set in the status object,
// and 0 will be returned.
TF_CAPI_EXPORT extern uint64_t TF_DeviceListIncarnation(