docs: public boolean isInNavigation() {
  
          if (m_hasNav == null) {
              // use "lazy initializing"
              Object o1 = getProperties().get(CmsPropertyDefinition.PROPERTY_NAVTEXT);
              Object o2 = getProperties().get(CmsPropertyDefinition.PROPERTY_NAVPOS);
              m_hasNav = Boolean.valueOf(((o1 != null) || (o2 != null)) && !CmsResource.isTemporaryFileName(m_sitePath));
          }
          return m_hasNav.booleanValue();
      }