docs: boolean isDoubleAlias(String aliasName) {
  
          CmsSiteMatcher testAlias = new CmsSiteMatcher(aliasName);
          int count = 0;
          for (Component c : m_aliases) {
              if (c instanceof CmsRemovableFormRow<?>) {
                  String alName = (String)((CmsRemovableFormRow<? extends AbstractField<?>>)c).getInput().getValue();
                  if (testAlias.equals(new CmsSiteMatcher(alName))) {
                      count++;
                  }
              }
          }
          return count > 1;
      }