docs: public static int sizeUTF(String str) {
          int len=str != null? str.length() : 0, utflen=2;
          if(len == 0)
              return utflen;
          for(int i = 0; i < len; i++) {
             int  c=str.charAt(i);
              if((c >= 0x0001) && (c <= 0x007F))
                  utflen++;
              else if (c > 0x07FF)
                  utflen += 3;
              else
                  utflen += 2;
          }
          return utflen;
      }