func (p SecGroupPage) IsEmpty() (bool, error) {
	is, err := ExtractGroups(p)
	if err != nil {
		return true, nil
	}
	return len(is) == 0, nil
}
IsEmpty checks whether a SecGroupPage struct is empty.
package groups
import (
	"github.com/mitchellh/mapstructure"
	"github.com/rackspace/gophercloud"
	"github.com/rackspace/gophercloud/openstack/networking/v2/extensions/security/rules"
	"github.com/rackspace/gophercloud/pagination"
)
type SecGroup struct {
	ID string
	Name string
	Description string
	Rules []rules.SecGroupRule `json:"security_group_rules" mapstructure:"security_group_rules"`
	TenantID string `json:"tenant_id" mapstructure:"tenant_id"`
}
type SecGroupPage struct {
	pagination.LinkedPageBase
}
func (p SecGroupPage) NextPageURL() (string, error) {
	type resp struct {
		Links []gophercloud.Link `mapstructure:"security_groups_links"`
	}
	var r resp
	err := mapstructure.Decode(p.Body, &r)
	if err != nil {
		return "", err
	}
	return gophercloud.ExtractNextURL(r.Links)
}