/// <summary>
        /// Query the entitlement information defined with Epic Online Services.
        /// A set of entitlement names can be provided to filter the set of entitlements associated with the account.
        /// This data will be cached for a limited time and retrieved again from the backend when necessary.
        /// Use <see cref="CopyEntitlementByIndex" />, <see cref="CopyEntitlementByNameAndIndex" />, and <see cref="CopyEntitlementById" /> to get the entitlement details.
        /// Use <see cref="GetEntitlementsByNameCount" /> to retrieve the number of entitlements with a specific entitlement name.
        /// </summary>
        /// <param name="options">structure containing the account and entitlement names to retrieve</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 QueryEntitlements(QueryEntitlementsOptions options, object clientData, OnQueryEntitlementsCallback completionDelegate)
        {
            var optionsInternal = Helper.CopyProperties <QueryEntitlementsOptionsInternal>(options);

            var completionDelegateInternal = new OnQueryEntitlementsCallbackInternal(OnQueryEntitlements);
            var clientDataAddress          = IntPtr.Zero;

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

            EOS_Ecom_QueryEntitlements(InnerHandle, ref optionsInternal, clientDataAddress, completionDelegateInternal);
            Helper.TryMarshalDispose(ref optionsInternal);
        }
 private static extern void EOS_Ecom_QueryEntitlements(IntPtr handle, ref QueryEntitlementsOptionsInternal options, IntPtr clientData, OnQueryEntitlementsCallbackInternal completionDelegate);