func (limiter *Limiter) GetIPKey(r *http.Request) string {
	return limiter.GetIPWithMask(r).String()
}
GetIPKey extracts IP from request and returns hashed IP to use as store key.
package limiter
import (
	"net"
	"net/http"
	"strings"
)
var (
	DefaultIPv4Mask = net.CIDRMask(32, 32)
	DefaultIPv6Mask = net.CIDRMask(128, 128)
)
func (limiter *Limiter) GetIP(r *http.Request) net.IP {
	return GetIP(r, limiter.Options)
}
func (limiter *Limiter) GetIPWithMask(r *http.Request) net.IP {
	return GetIPWithMask(r, limiter.Options)
}