code: public static Nengo ofKanji(String kanji) {
  
          Nengo nengo = KANJI_TO_NENGO.get(kanji);
  
          if (nengo == null) {
              throw new IllegalArgumentException(
                  "Could not find any nengo for Japanese kanji: " + kanji);
          } else {
              return nengo;
          }
  
      }
docs: /*[deutsch]
  <p>Versucht, einen passenden Nengo zur in japanischen Kanji angegebenen Repr&auml;sentation zu finden. </p>
  
  @param   kanji   the representation in japanese kanji
  @return  suitable nengo with same kanji
  @throws  IllegalArgumentException if no suitable nengo could be found for given kanji representation