code: public List<I_CmsHistoryResource> readAllAvailableVersions(CmsResource resource) throws CmsException {
  
          return m_securityManager.readAllAvailableVersions(m_context, resource);
      }
docs: Reads all available versions for a given resource.<p>
  
  @param resource the resource for which to read the versions
  @return the list of historical versions of the resource
  
  @throws CmsException if something goes wrong