code: public void setPreserveLibModules(String preserveLibModules) {
  
          if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(preserveLibModules)) {
              String[] modules = preserveLibModules.split(",");
              m_preserveLibModules = Arrays.asList(modules);
          } else {
              m_preserveLibModules = Collections.emptyList();
          }
      }
docs: Sets the list of modules where the included libs should be preserved during update.<p>
  Called from step_5_update_modules.jsp.<p>
  
  @param preserveLibModules the comma separated list of module names