src/Type/Definition/Type.php
public static function assertType($type)
    {
        Utils::invariant(
            self::isType($type),
            'Expected ' . Utils::printSafe($type) . ' to be a GraphQL type.'
        );

        return $type;
    }
public static function assertType($type)
    {
        Utils::invariant(
            self::isType($type),
            'Expected ' . Utils::printSafe($type) . ' to be a GraphQL type.'
        );

        return $type;
    }
@param mixed $type

@return mixed