@Override
    protected Map<StoreKey, StoreKey> convertKeys(Collection<? extends StoreKey> input) throws Exception {
      if (exception != null) {
        throw exception;
      }
      Map<StoreKey, StoreKey> output = new HashMap<>();
      if (input != null) {
        for (StoreKey storeKey : input) {
          if (returnKeyIfAbsent && !conversionMap.containsKey(storeKey)) {
            output.put(storeKey, storeKey);
          } else {
            output.put(storeKey, conversionMap.get(storeKey));
          }
        }
      }
      return output;
    }
Set conversionMap for reference.
@param conversionMap used by this {@link MockStoreKeyConverter} instance
ambry-test-utils/src/main/java/com/github/ambry/store/MockStoreKeyConverterFactory.java