public function findOperator($name)
    {
        $operator = ucfirst($name);
        foreach (array_keys($this->operatorNamespaces) as $namespace) {
            $class = $namespace . '\\' . $operator;
            if (class_exists($class)) {
                return $class;
            }
        }

        throw new \LogicException(sprintf('Unknown operator: "%s"', $name));
    }