Glassfy.initialize(apiKey:"8NOV6FQBHHRJ4F9N2HV0HUXOQ5LL0QA3")
              
              Glassfy.offerings { (offers, error) in
                guard let offer = offers?["my_offering"],
                  let sku = offer.skus.first else { return }
              
              Glassfy.purchase(sku: sku) {(t, error) in
                if let permission = t?.permissions["premium"],
                    permission.isValid {
                      // unlock premium
                    }
                }
              }
              

[Glassfy initializeWithAPIKey:@"8NOV6FQBHHRJ4F9N2HV0HUXOQ5LL0QA3" watcherMode:NO];
              ​
              [Glassfy offeringsWithCompletion:^(GYOfferings *offers, NSError *err) {
              GYOffering *offering = offers[@"my_offering"];
              if (offering == nil)
              return;
              GYSku *sku = offering.skus.firstObject;
              
                  [Glassfy purchaseSku:sku completion:^(GYTransaction *t,NSError *error) {
                      if (t == nil)
                          return;
                      GYPermission *p = t.permissions[@"premium"];
                      if (p != nil && p.isValid) {
                          // unlock premium
                      }
                  }];
              
              }];
              

Glassfy.initialize(this, "8NOV6FQBHHRJ4F9N2HV0HUXOQ5LL0QA3", false, null)
              Glassfy.offerings { offers, error ->
                  val offer = offers?.all?.find {  o -> o.offeringId == "my_offering" }
                  val sku = offer?.skus?.firstOrNull() ?: return@offerings
              
                  Glassfy.purchase(this, sku) { transaction, err ->
                      transaction?.permissions
                          ?.all
                          ?.find { p -> p.permissionId == "premium" && p.isValid }
                          ?.let {
                              // unlock premium
                          }
                  }
              }
              

Glassfy.initialize(this, "8NOV6FQBHHRJ4F9N2HV0HUXOQ5LL0QA3", false, null);
              Glassfy.offerings((offers, error) -> {
                  Sku sku = null;
                  if (offers != null) {
                      for (Offering o : offers.getAll()) {
                          if (o.getOfferingId().equals("my_offering") && o.getSkus().size() > 0) {
                              sku = o.getSkus().get(0);
                              break;
                          }
                      }
                  }
                  if (sku == null) { return; }
                  Glassfy.purchase(this, sku, (transaction, err) -> {
                      if (transaction != null) {
                          for (Permission p : transaction.getPermissions().getAll()) {
                              if (p.getPermissionId().equals("premium") && p.isValid()) {
                                  // unlock premium
                              }
                          }
                      }
                  });
              });
              

await Glassfy.initialize("8NOV6FQBHHRJ4F9N2HV0HUXOQ5LL0QA3");
              var offerings = await Glassfy.offerings();
              var offering = offerings.all
                ?.singleWhere((offering) => offering.offeringId == "my_offering");
              var sku = offering?.skus?.first;
              if (sku != null) {
              var transaction = await Glassfy.purchaseSku(sku);
              var permission = transaction.permissions?.all
                  ?.singleWhere((permission) => permission.permissionId== "premium");
              if (permission?.isValid==true) {
                // unlock premium
              }
              

await Glassfy.initialize("8NOV6FQBHHRJ4F9N2HV0HUXOQ5LL0QA3", false);
              ​
              const offerings = await Glassfy.offerings();
              const offering = offerings.all.find(
                (off) => off.identifier === "my_offering"
              );
              if (!offering) return;
              const sku = offering.skus[0];
              const transaction = await Glassfy.purchaseSku(sku);
              const permission = transaction.permissions.all.find(
                (p) => p.permissionIdentifier === "premium"
              );
              if (permission?.isValid) {
                // unlock premium
              }
              

await Glassfy.initialize({
                  apiKey: "8NOV6FQBHHRJ4F9N2HV0HUXOQ5LL0QA3",
                  watcherMode: false
              });
              ​
              const offerings = await Glassfy.offerings();
              const offering = offerings.all.
              find((offering) => offering.offeringId == "my_offering");
              if (!offering)
                  return;
              const sku = offering.skus[0];
              const transaction = await Glassfy.purchaseSku({ sku });
              const permission = transaction.permissions.all.
              find((permission) => permission.permissionId == "premium");
              ​
              if (permission?.isValid) {
                  // unlock premium
              }