func (a int64Amount) Sign() int {
	switch {
	case a.value == 0:
		return 0
	case a.value > 0:
		return 1
	default:
		return -1
	}
}
Sign returns 0 if the value is zero, -1 if it is less than 0, or 1 if it is greater than 0.
package resource
import (
	"math/big"
	"strconv"
	inf "gopkg.in/inf.v0"
)
type Scale int32
func (s Scale) infScale() inf.Scale {
	return inf.Scale(-s)  
}
const (
	Nano  Scale = -9
	Micro Scale = -6
	Milli Scale = -3
	Kilo  Scale = 3
	Mega  Scale = 6
	Giga  Scale = 9
	Tera  Scale = 12
	Peta  Scale = 15
	Exa   Scale = 18
)
var (
	Zero = int64Amount{}
	zeroBytes = []byte("0")
)
type int64Amount struct {
	value int64
	scale Scale
}