private static IElementType getToken(int keywordSetIndex) {
    switch(keywordSetIndex) {
      case 0: return CustomHighlighterTokenType.KEYWORD_1;
      case 1: return CustomHighlighterTokenType.KEYWORD_2;
      case 2: return CustomHighlighterTokenType.KEYWORD_3;
      case 3: return CustomHighlighterTokenType.KEYWORD_4;
    }
    throw new AssertionError(keywordSetIndex);
  }
private static IElementType getToken(int keywordSetIndex)