typed.go
func (t Typed) Ints64Or(key string, d []int64) []int64 {
	n, ok := t.Ints64If(key)
	if ok {
		return n
	}
	return d
}
func (t Typed) Ints64Or(key string, d []int64) []int64 {
	n, ok := t.Ints64If(key)
	if ok {
		return n
	}
	return d
}
// Returns an slice of ints, or the specified slice
// if the key doesn't exist or isn't a valid []int.
// Some conversion is done to handle the fact that JSON ints
// are represented as floats.