executionContext.setSigner(signer);
executionContext.setCredentials(credentials);
executionContext.setCustomBackoffStrategy(com.amazonaws.internal.DynamoDBBackoffStrategy.DEFAULT);
JsonErrorResponseHandler errorResponseHandler = new JsonErrorResponseHandler(exceptionUnmarshallers);
awsRequestMetrics.startEvent(Field.ClientExecuteTime.name());
X result = (X) client.execute(request, responseHandler, errorResponseHandler, executionContext);
awsRequestMetrics.endEvent(Field.ClientExecuteTime.name());