code: public CmsXmlContentDefinition getCachedContentDefinition(String systemId) {
  
          String cacheKey = getCacheKeyForCurrentProject(systemId);
          CmsXmlContentDefinition result = m_cacheContentDefinitions.get(cacheKey);
          if ((result != null) && LOG.isDebugEnabled()) {
              LOG.debug(Messages.get().getBundle().key(Messages.LOG_CACHE_LOOKUP_SUCCEEDED_1, cacheKey));
          }
          return result;
      }
docs: Looks up the given XML content definition system id in the internal content definition cache.<p>
  
  @param systemId the system id of the XML content definition to look up
  
  @return the XML content definition found, or null if no definition is cached for the given system id