code: public AssetInfo getImplAsset(String className) throws ServiceException {
          int lastDot = className.lastIndexOf('.');
          if (lastDot > 0 && lastDot < className.length() - 1) {
              String assetRoot = className.substring(0, lastDot) + "/" + className.substring(lastDot + 1);
                  AssetInfo implAsset = getAsset(assetRoot + ".java");
                  if (implAsset == null)
                      return getAsset(assetRoot + ".kt");
          }
          return null;
      }
docs: Returns either Java or Kotlin asset implementor for a class.  Null if not found.