code: private CmsResource getResource(CmsUUID structureId) {
  
          CmsResource resource = m_resources.get(structureId);
          if (resource == null) {
              try {
                  resource = m_cms.readResource(structureId, CmsResourceFilter.ALL);
                  m_resources.put(structureId, resource);
              } catch (CmsException e) {
                  LOG.info(e.getLocalizedMessage(), e);
              }
          }
          return resource;
      }
docs: Reads a resource with a given id, but will get a resource from a cache if it has already been read before.<p>
  If an error occurs, null will be returned.
  
  @param structureId the structure id
  @return the resource with the given structure id