docs: private void setupVersionsToKeepComboBox() {
  
          final List<Integer> items = new ArrayList<Integer>();
  
          //Add default values to ComboBox
          for (int i = 0; i < 10; i++) {
              m_numberVersionsToKeep.addItem(new Integer(i));
              items.add(new Integer(i));
          }
          for (int i = 10; i <= VERSIONS_MAX; i += 5) {
              m_numberVersionsToKeep.addItem(new Integer(i));
              items.add(new Integer(i));
          }
          m_numberVersionsToKeep.setPageLength(m_numberVersionsToKeep.size());
          m_numberVersionsToKeep.setNullSelectionAllowed(false);
          m_numberVersionsToKeep.setTextInputAllowed(true);
  
          //Alow user to enter other values
          m_numberVersionsToKeep.setNewItemsAllowed(true);
          m_numberVersionsToKeep.setNewItemHandler(new NewItemHandler() {
  
              private static final long serialVersionUID = -1962380117946789444L;
  
              public void addNewItem(String newItemCaption) {
  
                  int num = CmsStringUtil.getIntValue(newItemCaption, -1, "user entered version number is not a number");
                  if ((num > 1) && !items.contains(new Integer(num))) {
                      m_numberVersionsToKeep.addItem(new Integer(num));
                      m_numberVersionsToKeep.select(new Integer(num));
                  }
              }
          });
  
          //Select the value which correspons to current history setting.
          int numberHistoryVersions = OpenCms.getSystemInfo().getHistoryVersions();
          if (numberHistoryVersions == CmsFileHistoryApp.NUMBER_VERSIONS_DISABLED) {
              numberHistoryVersions = 0;
          }
          if (numberHistoryVersions == CmsFileHistoryApp.NUMBER_VERSIONS_UNLIMITED) {
              numberHistoryVersions = VERSIONS_MAX;
          }
          m_numberVersionsToKeep.select(new Integer(numberHistoryVersions));
      }