docs: function indexOf(haystack, needle, i) {
      if (!Buffer.isBuffer(needle)) needle = new Buffer(needle);
      if (typeof i === 'undefined') i = 0;
      var l = haystack.length - needle.length + 1;
      while (i<l) {
        var good = true;
        for (var j=0, n=needle.length; j<n; j++) {
          if (haystack[i+j] !== needle[j]) {
            good = false;
            break;
          }
        }
        if (good) return i;
        i++;
      }
      return -1;
    }