code: public String getProperty(String strKey, Map<String, Object> properties)
      {
          String strProperty = super.getProperty(strKey, properties);
          if (strProperty == null)
              if (!m_proxyTask.isShared())
                  strProperty = m_proxyTask.getProperty(strKey);
          return strProperty;
      }
docs: Get the servlet's property.
  For Ajax proxies, the top level proxy is shared among sessions. since it is not unique, don't return property.