code: @Override
      public boolean containsKey(Object key, boolean includeDiskCache) {
          ValidateUtility.objectNotNull(key, "key");
          boolean found = cache.containsCacheId(key);
          if (found) {
              return found;
          }
          if (includeDiskCache) {
              if (cache instanceof CacheProviderWrapper) {
                  if (tc.isDebugEnabled())
                      Tr.debug(tc, "containKey instanceof CacheProviderWrapper");
                  CacheProviderWrapper cpw = (CacheProviderWrapper) cache;
                  if (cpw.featureSupport.isDiskCacheSupported())
                      found = cache.containsKeyDisk(key);
              } else {
                  if (tc.isDebugEnabled())
                      Tr.debug(tc, "containKey not instanceof CacheProviderWrapper");
                  found = cache.containsKeyDisk(key);
              }
          }
          return found;
      }
docs: Returns <tt>true</tt> if this map contains a mapping for the specified
  key.
  
  @param key key whose presence in this map is to be tested.
  @param includeDiskCache true to check the specified key contained in the memory or
  disk maps; false to check the specified key contained in the memory map.
  @return <tt>true</tt> if this map contains a mapping for the specified
  key.
  
  @throws ClassCastException if the key is of an inappropriate type for
  this map.
  @throws NullPointerException if the key is <tt>null</tt> and this map
  does not not permit <tt>null</tt> keys.