func (r commonResult) Extract() (*Service, error) {
	if r.Err != nil {
		return nil, r.Err
	}
	var res struct {
		Service `json:"service"`
	}
	err := mapstructure.Decode(r.Body, &res)
	return &res.Service, err
}
Extract interprets a GetResult, CreateResult or UpdateResult as a concrete Service.
An error is returned if the original call or the extraction failed.
package services
import (
	"github.com/rackspace/gophercloud"
	"github.com/rackspace/gophercloud/pagination"
	"github.com/mitchellh/mapstructure"
)
type commonResult struct {
	gophercloud.Result
}