code: public TranslationRequestDataChangeSet setTargetLanguagesByBundle(
              Map<String, Set<String>> targetLanguagesByBundle) {
          // TODO - check empty map?
          if (targetLanguagesByBundle == null) {
              throw new NullPointerException("The input map is null.");
          }
          this.targetLanguagesByBundle = targetLanguagesByBundle;
          return this;
      }
docs: Sets a map containing target languages indexed by bundle IDs. This method adopts
  the input map without creating a safe copy.
  
  @param targetLanguagesByBundle   A map containing target languages indexed by
  bundle IDs.
  @return  This object.
  @throws NullPointerException When the input <code>targetLanguagesByBundle</code> is null.