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

        executionContext.setCredentialsProvider(CredentialUtils.getCredentialsProvider(request.getOriginalRequest(), awsCredentialsProvider));

        return doInvoke(request, responseHandler, executionContext, cachedEndpoint, uriFromEndpointTrait);
    }
Normal invoke with authentication. Credentials are required and may be overriden at the request level.
aws-java-sdk-cloud9/src/main/java/com/amazonaws/services/cloud9/AWSCloud9Client.java