var OfflineDisk StorageAPI // zero value is nil

// erasureObjects - Implements ER object layer.
type erasureObjects struct {
	setDriveCount      int
	defaultParityCount int

	setIndex  int
	poolIndex int

	// getDisks returns list of storageAPIs.
	getDisks func() []StorageAPI

	// getLockers returns list of remote and local lockers.
	getLockers func() ([]dsync.NetLocker, string)