code: public void addScope(String scope, int maxItemsInMemory) throws Exception {
          // Ignore maxItemsInMemory, since we don't run an eviction algorithm.
          scopeCaches.put(scope, new ConcurrentHashMap<Object, CacheItem>());
      }
docs: Adds a new scope. The scope is an instance of {@link ConcurrentHashMap}.
  
  @param scope            the name of the scope
  @param maxItemsInMemory the maximum number of items in memory, before they are evicted
  @throws Exception