type IAMStorageAPI interface {
	// The role of the read-write lock is to prevent go routines from
	// concurrently reading and writing the IAM storage. The (r)lock()
	// functions return the iamCache. The cache can be safely written to
	// only when returned by `lock()`.
	lock() *iamCache
	unlock()
	rlock() *iamCache
	runlock()
	getUsersSysType() UsersSysType

	m, ok := isObjectDangling(metaArr, errs, dataErrsByPart)
	if !ok {
		// We only come here if we cannot figure out if the object
		// can be deleted safely, in such a scenario return ReadQuorum error.
		return FileInfo{}, errErasureReadQuorum
	}
	tags := make(map[string]string, 16)
	tags["set"] = strconv.Itoa(er.setIndex)
	tags["pool"] = strconv.Itoa(er.poolIndex)

		// are multiple openid provider configurations with the same ID
		// provider. We lookup the provider associated with some one of
		// the roleARNs to check if the user still exists. If they don't
		// we can safely remove credentials for this parent user
		// associated with any of the provider configurations.
		//
		// If there is no roleARN mapped to the user, the user may be
		// coming from a policy claim based openid provider.

// * size_t is used to represent byte sizes of objects that are
//   materialized in the address space of the calling process.
// * int is used as an index into arrays.
// * Deletion functions are safe to call on nullptr.
//
// Questions left to address:
// * Might at some point need a way for callers to provide their own Env.
// * Maybe add TF_TensorShape that encapsulates dimension info.
//
// Design decisions made:

	}
	ddir, err = uuid.Parse(dataDir)
	if err != nil {
		return 0
	}
	return x.SharedDataDirCount(uv, ddir)
}

// AddLegacy adds a legacy version, is only called when no prior
// versions exist, safe to use it by only one function in xl-storage(RenameData)
func (x *xlMetaV2) AddLegacy(m *xlMetaV1Object) error {
	if !m.valid() {
		return errFileCorrupt
	}
	m.VersionID = nullVersionID

  ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);
  TF_GraphCopyFunction(host_graph_, func_, nullptr, s_);
  ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

  // Delete the gradient func.
  // It is safe to delete after adding a copy to host graph.
  TF_DeleteFunction(grad_func);

  // Check that GraphDef did not change
  GraphDef gdef2;
  GetGraphDef(host_graph_, &gdef2);