private <X, Y extends AmazonWebServiceRequest> Response<X> doInvoke(Request<Y> request, HttpResponseHandler<AmazonWebServiceResponse<X>> responseHandler,
            ExecutionContext executionContext, URI discoveredEndpoint, URI uriFromEndpointTrait) {

        if (discoveredEndpoint != null) {
            request.setEndpoint(discoveredEndpoint);
            request.getOriginalRequest().getRequestClientOptions().appendUserAgent("endpoint-discovery");
        } else if (uriFromEndpointTrait != null) {
            request.setEndpoint(uriFromEndpointTrait);
        } else {
            request.setEndpoint(endpoint);
        }

        request.setTimeOffset(timeOffset);

        HttpResponseHandler<AmazonServiceException> errorResponseHandler = protocolFactory.createErrorResponseHandler(new JsonErrorResponseMetadata());

        return client.execute(request, responseHandler, errorResponseHandler, executionContext);
    }
Invoke the request using the http client. Assumes credentials (or lack thereof) have been configured in the
ExecutionContext beforehand.
aws-java-sdk-servicequotas/src/main/java/com/amazonaws/services/servicequotas/AWSServiceQuotasClient.java