ditto
Add a query parameter with the given key and value. If one already exists, there will now be two query parameters with the given name.
Clone this set of query parameters.
Get a range over the query parameter values for the given key.
Add a query parameter with the given key and value. If there are any existing parameters with the same key, they are removed and overwritten.
A range over the query parameters.
Convert this set of query parameters into a query string.
A collection of query parameters.
This is effectively a multimap of string -> strings.