private void addModule(Module other) { List<Module> modules = getModules(); Module currentModule = modules.stream() // Check if there's already a module with the same name. .filter(module -> StringUtils.equals(module.getId(), other.getId())) .findAny() .orElse(null); if (currentModule == null) { // Append new module. modules.add(other); } else { // Append the other module into the existing module with the same name. currentModule.append(other); } }