}
@Override
public void preProcessWebXmlElement(WebApp webApp, MergeContext context) throws DeploymentException {
if (webApp.getSessionConfig().size() == 1) {
SessionConfig sessionConfig = webApp.getSessionConfig().get(0);
mergeSessionConfig(webApp, sessionConfig, context, ElementSource.WEB_XML);
context.setAttribute("session-config", sessionConfig);
} else if (webApp.getSessionConfig().size() > 1) {
throw new DeploymentException(WebDeploymentMessageUtils.createMultipleConfigurationWebAppErrorMessage("session-config"));
}