protected override Task <MegafonContact> InvokeOnContact(MegafonCallbackOptions <THandler> options, ContactRequest request)
 {
     return(options.InvokeOnContact(_handler, request));
 }
 protected abstract Task <MegafonContact> InvokeOnContact(TOptions options, ContactRequest request);
 protected override async Task <MegafonContact> InvokeOnContact(MegafonCallbackOptions options, ContactRequest request)
 {
     return(await options.InvokeOnContact(request));
 }