public static function getOperatorsList()
    {
        // Build $operatorValues if this is the first call
        if (null === static::$operatorValues) {
            static::$operatorValues = [];
            $refClass = new \ReflectionClass(static::class);
            $classConstants = $refClass->getConstants();
            $className = $refClass->getShortName();

            $constantPrefix = 'OPERATOR_';
            foreach ($classConstants as $key => $val) {
                if (\substr($key, 0, \strlen($constantPrefix)) === $constantPrefix) {
                    static::$operatorValues[] = $val;
                }
            }
        }

        return static::$operatorValues;
    }