exceptionUnmarshallers = new ArrayList<Unmarshaller<AmazonServiceException, Node>>();
exceptionUnmarshallers.add(new LegacyErrorUnmarshaller());
setEndpoint("ec2.amazonaws.com");
signer = new QueryStringSigner(awsCredentials);
requestHandlers = new HandlerChainFactory().newRequestHandlerChain(
"/com/amazonaws/services/ec2/request.handlers");
client = new HttpClient(clientConfiguration);
}