public function setScope($scope)
    {
        if (in_array($scope, TableCellScope::asArray(), true) === true || $scope === -1) {
            $this->scope = $scope;
        } else {
            $msg = "The 'scope' argument must be a value from the TableCellScope enumeration, '" . $scope . "' given.";
            throw new InvalidArgumentException($msg);
        }
    }