GraphQL\Type\Definition\EnumType::getValueLookup PHP Method

    private function getValueLookup()
    {
        if (null === $this->valueLookup) {
            $this->valueLookup = new Utils\MixedStore();
            foreach ($this->getValues() as $valueName => $value) {
                $this->valueLookup->offsetSet($value->value, $value);
            }
        }
        return $this->valueLookup;
    }