code: func (f *FakeCloud) InstanceShutdownByProviderID(ctx context.Context, providerID string) (bool, error) {
  	f.addCall("instance-shutdown-by-provider-id")
  	return f.NodeShutdown, f.ErrShutdownByProviderID
  }
docs: // InstanceShutdownByProviderID returns true if the instances is in safe state to detach volumes