ExecutionContext executionContext = createExecutionContext();
executionContext.setSigner(signer);
executionContext.setCredentials(credentials);
executionContext.setCustomBackoffStrategy(com.amazonaws.internal.DynamoDBBackoffStrategy.DEFAULT);
JsonErrorResponseHandler errorResponseHandler = new JsonErrorResponseHandler(exceptionUnmarshallers);
return (X)client.execute(request, responseHandler, errorResponseHandler, executionContext);
}