func (opts ListOpts) ToSubnetListQuery() (string, error) {
	q, err := gophercloud.BuildQueryString(opts)
	return q.String(), err
}
ToSubnetListQuery formats a ListOpts into a query string.
package subnets
import (
	"github.com/gophercloud/gophercloud"
	"github.com/gophercloud/gophercloud/pagination"
)
type ListOptsBuilder interface {
	ToSubnetListQuery() (string, error)
}
type ListOpts struct {
	Name       string `q:"name"`
	EnableDHCP *bool  `q:"enable_dhcp"`
	NetworkID  string `q:"network_id"`
	TenantID   string `q:"tenant_id"`
	IPVersion  int    `q:"ip_version"`
	GatewayIP  string `q:"gateway_ip"`
	CIDR       string `q:"cidr"`
	ID         string `q:"id"`
	Limit      int    `q:"limit"`
	Marker     string `q:"marker"`
	SortKey    string `q:"sort_key"`
	SortDir    string `q:"sort_dir"`
}