func NewError(s string) error { return ErrorString(s) }

func (e ErrorString) Is(target error) bool {
	switch target {
	case oserror.ErrPermission:
		return checkErrMessageContent(e, "permission denied")
	case oserror.ErrExist:
		return checkErrMessageContent(e, "exists", "is a directory")
	case oserror.ErrNotExist:
		return checkErrMessageContent(e, "does not exist", "not found",
			"has been removed", "no parent")
	case errors.ErrUnsupported: