@Override
  public StoreKey getConverted(StoreKey storeKey) {
    return getConvertedKey(storeKey, conversionCache.containsKey(storeKey), conversionCache.get(storeKey));
  }
@param storeKey storeKey you want the converted version of.  If the key was not apart
                of a previous {@link #convert(Collection)} call, method may throw
                IllegalStateException
@return
ambry-api/src/main/java/com/github/ambry/store/AbstractStoreKeyConverter.java