// returns file mode creation mask.
func getUmask() int {
	mask := syscall.Umask(0)
	syscall.Umask(mask)
	return mask
}

// Tests if the directory and file creations happen with proper umask.
func TestIsValidUmaskVol(t *testing.T) {
	tmpPath := t.TempDir()
	testCases := []struct {
		volName       string
		expectedUmask int
	}{
		{"is-this-valid", getUmask()},
	}

func NewDummyDataGen(totalLength, skipOffset int64) io.ReadSeeker {
	if totalLength < 0 {
		panic("Negative length passed to DummyDataGen!")
	}
	if skipOffset < 0 {
		panic("Negative rotations are not allowed")
	}

	skipOffset %= int64(len(alphabets))
	const multiply = 100
	as := bytes.Repeat(alphabets, multiply)
	b := as[skipOffset : skipOffset+int64(len(alphabets)*(multiply-1))]
	return &DummyDataGen{