internal static void OnQueryOffers(IntPtr address)
        {
            OnQueryOffersCallback   callback     = null;
            QueryOffersCallbackInfo callbackInfo = null;

            if (Helper.TryGetAndRemoveCallback <OnQueryOffersCallback, QueryOffersCallbackInfoInternal, QueryOffersCallbackInfo>(address, out callback, out callbackInfo))
            {
                callback(callbackInfo);
            }
        }
        /// <summary>
        /// Query for a list of catalog offers defined with Epic Online Services.
        /// This data will be cached for a limited time and retrieved again from the backend when necessary.
        /// </summary>
        /// <param name="options">structure containing filter criteria</param>
        /// <param name="clientData">arbitrary data that is passed back to you in the CompletionDelegate</param>
        /// <param name="completionDelegate">a callback that is fired when the async operation completes, either successfully or in error</param>
        public void QueryOffers(QueryOffersOptions options, object clientData, OnQueryOffersCallback completionDelegate)
        {
            var optionsInternal = Helper.CopyProperties <QueryOffersOptionsInternal>(options);

            var completionDelegateInternal = new OnQueryOffersCallbackInternal(OnQueryOffers);
            var clientDataAddress          = IntPtr.Zero;

            Helper.AddCallback(ref clientDataAddress, clientData, completionDelegate, completionDelegateInternal);

            EOS_Ecom_QueryOffers(InnerHandle, ref optionsInternal, clientDataAddress, completionDelegateInternal);
            Helper.TryMarshalDispose(ref optionsInternal);
        }