func (s *Xor64Source) next() uint64 {
	x := xor64(uint64(*s))
	*s = Xor64Source(x)
	return x
}
func (s *Xor64Source) next() uint64 {
	x := xor64(uint64(*s))
	*s = Xor64Source(x)
	return x
}
func ( s * Xor64Source ) next ( ) uint64 { x := xor64 ( uint64 ( * s ) ) * s = Xor64Source ( x ) return x }
// next advances the generators internal state to the next value and returns
// this value as an uint64.
next advances the generators internal state to the next value and returns this value as an uint64 .