code: function isImpliedEndTagRequired(tn) {
      switch (tn.length) {
          case 1:
              return tn === $.P;
  
          case 2:
              return tn === $.RB || tn === $.RP || tn === $.RT || tn === $.DD || tn === $.DT || tn === $.LI;
  
          case 3:
              return tn === $.RTC;
  
          case 6:
              return tn === $.OPTION;
  
          case 8:
              return tn === $.OPTGROUP;
      }
  
      return false;
  }
docs: OPTIMIZATION: Integer comparisons are low-cost, so we can use very fast tag name length filters here. It's faster than using dictionary.