func GetStatusCode(err error, default_code int) int {
	rv := errors.GetData(err, statusCode)
	sc, ok := rv.(int)
	if ok {
		return sc
	}
	return default_code
}
GetStatusCode will return the status code associated with an error, and
default_code if none is found.
package errhttp
import (
	"fmt"
	"github.com/spacemonkeygo/errors"
)
var (
	statusCode = errors.GenSym()
	errorBody  = errors.GenSym()
)
func SetStatusCode(code int) errors.ErrorOption {
	return errors.SetData(statusCode, code)
}
func OverrideErrorBody(message string) errors.ErrorOption {
	return errors.SetData(errorBody, message)
}
func RestoreDefaultErrorBody() errors.ErrorOption {
	return errors.SetData(errorBody, nil)
}