const hash/fnv.magic64a

5 uses

	hash/fnv (current package)
		fnv.go#L217: 	magic64a         = "fnv\x04"
		fnv.go#L249: 	b = append(b, magic64a...)
		fnv.go#L304: 	if len(b) < len(magic64a) || string(b[:len(magic64a)]) != magic64a {