docs: function parseOptions(input, callback, keyValueDelim, groupDelim) {
      var groups = groupDelim ? input.split(groupDelim) : [input];
      for (var i in groups) {
        if (typeof groups[i] !== "string") {
          continue;
        }
        var kv = groups[i].split(keyValueDelim);
        if (kv.length !== 2) {
          continue;
        }
        var k = kv[0];
        var v = kv[1];
        callback(k, v);
      }
    }