public function parseLiteral($valueNode, ?array $variables = null)
    {
        if ($valueNode instanceof EnumValueNode) {
            $lookup = $this->getNameLookup();
            if (isset($lookup[$valueNode->value])) {
                $enumValue = $lookup[$valueNode->value];
                if ($enumValue !== null) {
                    return $enumValue->value;
                }
            }
        }

        // Intentionally without message, as all information already in wrapped Exception
        throw new Exception();
    }
public function parseLiteral($valueNode, ?array $variables = null)
    {
        if ($valueNode instanceof EnumValueNode) {
            $lookup = $this->getNameLookup();
            if (isset($lookup[$valueNode->value])) {
                $enumValue = $lookup[$valueNode->value];
                if ($enumValue !== null) {
                    return $enumValue->value;
                }
            }
        }

        // Intentionally without message, as all information already in wrapped Exception
        throw new Exception();
    }
@param Node         $valueNode
@param mixed[]|null $variables

@return null

@throws Exception