Making purchases

Glassfy.purchase(sku: premiumSku) { (transaction, e) in
    // update app status accordingly
    if let p = transaction?.permissions["aPermission"] {
        if p.isValid {
            // unlock aFeature
        } else {
            // lock aFeature
        }
    }
}

[Glassfy purchaseSku:premiumSku completion:^(GYTransaction *transaction, NSError *err) {
    GYPermissions *permissions = transaction.permissions;
    if (permissions) {
        GYPermission *p = permissions[@"aPermission"];
        if (p.isValid) {
            // unlock aFeature
        }
        else {
            // lock aFeature
        }
    }
}];

Glassfy.purchase(activity, sku) { transaction, err ->
    // update app status accordingly
    transaction?.permissions
        ?.all
        ?.firstOrNull { it.permissionId == "aPermission" }
        ?.also {
            if (it.isValid) {
                // unlock aFeature
            } else {
                // lock aFeature
            }
        }
}

Glassfy.purchase(activity, sku, new PurchaseCallback() {
    @Override
    public void onResult(@Nullable Transaction t, @Nullable GlassfyError err) {
        // update app status accordingly
        Permission permission = null;
        if (t != null) {
            for (Permission p : t.getPermissions().getAll()) {
                if (p.getPermissionId().equals("aPermission")) {
                    permission = p;
                }
            }
        }
        if (permission != null) {
            if (permission.isValid()) {
              // unlock aFeature
            } else {
              // lock aFeature
            }
        }
    }
});

try {
    var transaction = await Glassfy.purchaseSku(sku);

    var p = transaction.permissions?.all?.singleWhere((permission) => permission.permissionId == 'premium');
    if (p?.isValid==true) {
        // unlock aFeature
    }
    else {
        // lock aFeature
    }
} catch (e) {
  // initialization error
  [...]
}

try {
    const transaction = await Glassfy.purchaseSku(premiumSku );
    const permission = transaction.permissions.all.find((p) => p.permissionId === "aPermission");
    if (permission && permission.isValid) {
        // unlock aFeature
    }
} catch (e) {
  // initialization error
  [...]
}

try {
    const transaction = await Glassfy.purchaseSku({ sku: premiumSku });
    const permission = transaction.permissions.all.find((p) => p.permissionId === "aPermission");
    if (permission && permission.isValid) {
        // unlock aFeature
    }

} catch (e) {
  // initialization error
  [...]
}