docs: @SuppressWarnings("unchecked")
      private boolean isValid() {
  
          for (Field<?> field : m_fields) {
              if (!field.isValid()) {
                  field.focus();
  
                  return false;
              }
          }
          for (Component c : m_resources) {
              if (c instanceof CmsRemovableFormRow<?>) {
                  if (!((CmsRemovableFormRow<CmsPathSelectField>)c).getInput().isValid()) {
                      ((CmsRemovableFormRow<CmsPathSelectField>)c).getInput().focus();
                      return false;
                  }
              }
          }
          return true;
      }