code: private static String getClassFromDeclarationName(String fullDeclarationName) {
      String[] parts = fullDeclarationName.split("\\.prototype\\.");
      checkState(parts.length == 1 || parts.length == 2);
      if (parts.length == 2) {
        return parts[0];
      }
      return null;
    }
docs: From a provide name extract the class name.