warning of leak in Xcode

[superllanboy]

+(instancetype)reachabilityWithHostname:(NSString*)hostname
{
SCNetworkReachabilityRef ref = SCNetworkReachabilityCreateWithName(NULL, [hostname UTF8String]);
if (ref)
{
id reachability = [[self alloc] initWithReachabilityRef:ref];

    return reachability;
}

return nil;

}
Call to function 'SCNetworkReachabilityCreateWithName' returns a Core Foundation object of type SCNetworkReachabilityRef _Nullable with a +1 retain count
Assuming 'ref' is non-
Object leaked: object allocated and stored into 'ref' is not referenced later in this execution path and has a retain count of +1

i get the above error messages when analysing my project, and have no idea if this is a serious issue or not

please advise

thanks