You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: waf.go
    path of file: ./repos/streamdal/apps/server/vendor/github.com/DataDog/go-libddwaf/v2
    
    the code of the file until where you have to start completion: // Unless explicitly stated otherwise all files
    
func (e RunError) Error() string {
	switch e {
	case ErrInternal:
		return "internal waf error"
	case ErrTimeout:
		return "waf timeout"
	case ErrInvalidObject:
		return "invalid waf object"
	case ErrInvalidArgument:
		return "invalid waf argument"
	case ErrOutOfMemory:
		return "out of memory"
	case ErrEmptyRuleAddresses:
		return "empty rule addresses"
	default:
		return fmt.Sprintf("unknown waf error %d", e)
	}
}