only call netServiceBrowserWillSearch Method, don't call other delagete mathods

[zichengbohan]

I use DIscovery with this:
DiscoveryConfiguration *configurations = [[DiscoveryConfiguration alloc] initWithServiceType:@"_ptp.tcp." serviceNamePrefix:@""];
Discovery *discover = [[Discovery alloc] initWith:@[configurations] delegate:self serviceResolveTimeout:10];
[discover startDiscovery];
but, it only call netServiceBrowserWillSearch Method, don't call other delagete mathods.
public func netServiceBrowserWillSearch( browser: NetServiceBrowser) {
print("11111111111will");
}

public func netServiceDidStop(_ sender: NetService) {
    print("11111111111WillSearch");
}

public func netServiceBrowser(_ browser: NetServiceBrowser, didFind service: NetService, moreComing: Bool) {
    print("11111111111");
    guard let item = item(serviceBrowser: browser) else { return }
    
    if item.isValidForService(netService: service) {
        item.netServices.insert(service)
        service.delegate = self
        service.resolve(withTimeout: serviceResolveTimeout)
    }
}

public func netServiceBrowser(_ browser: NetServiceBrowser, didNotSearch errorDict: [String: NSNumber]) {
    print("11111111111");
 }