code: private static void initCaches() {
  
          if (m_cacheTemporary == null) {
              m_cacheTemporary = CmsMemoryMonitor.createLRUCacheMap(1024);
  
              m_cachePermanent = new ConcurrentHashMap<String, byte[]>(32);
  
              m_cacheContentDefinitions = CmsMemoryMonitor.createLRUCacheMap(CONTENT_DEFINITION_CACHE_SIZE);
          }
          if (OpenCms.getRunLevel() > OpenCms.RUNLEVEL_1_CORE_OBJECT) {
              if ((OpenCms.getMemoryMonitor() != null)
                  && !OpenCms.getMemoryMonitor().isMonitoring(CmsXmlEntityResolver.class.getName() + ".cacheTemporary")) {
                  // reinitialize the caches after the memory monitor is set up
                  Map<String, byte[]> cacheTemporary = CmsMemoryMonitor.createLRUCacheMap(128);
                  cacheTemporary.putAll(m_cacheTemporary);
                  m_cacheTemporary = cacheTemporary;
                  OpenCms.getMemoryMonitor().register(
                      CmsXmlEntityResolver.class.getName() + ".cacheTemporary",
                      cacheTemporary);
  
                  Map<String, byte[]> cachePermanent = new ConcurrentHashMap<String, byte[]>(32);
                  cachePermanent.putAll(m_cachePermanent);
                  m_cachePermanent = cachePermanent;
                  OpenCms.getMemoryMonitor().register(
                      CmsXmlEntityResolver.class.getName() + ".cachePermanent",
                      cachePermanent);
  
                  Map<String, CmsXmlContentDefinition> cacheContentDefinitions = CmsMemoryMonitor.createLRUCacheMap(
                      CONTENT_DEFINITION_CACHE_SIZE);
                  cacheContentDefinitions.putAll(m_cacheContentDefinitions);
                  m_cacheContentDefinitions = cacheContentDefinitions;
                  OpenCms.getMemoryMonitor().register(
                      CmsXmlEntityResolver.class.getName() + ".cacheContentDefinitions",
                      cacheContentDefinitions);
              }
          }
      }
docs: Initializes the internal caches for permanent and temporary system IDs.<p>