base32.go
func (e *encoding) Encode(x uint64) string {
	b := [12]byte{}
	for i := 0; i < 12; i++ {
		b[11-i] = e.encode[x&0x1f]
		x >>= 5
	}
	return string(b[:])
}
func (e *encoding) Encode(x uint64) string {
	b := [12]byte{}
	for i := 0; i < 12; i++ {
		b[11-i] = e.encode[x&0x1f]
		x >>= 5
	}
	return string(b[:])
}
// Encode bits of 64-bit word into a string.