Subclasses can use either {@link jakarta.servlet.http.HttpServlet#init(ServletConfig)}
or {@link jakarta.servlet.http.HttpServlet#init()} for initialization just like any other servlet.
The X-Response-Headers header can be used to pass through header values into the response.
The value should be a URL-encoded map of key-value pairs.
For example, to add a "Refresh: 1" header to the response to auto-refresh a page, the following
parameter can be specified: "/sample?X-Response-Headers={Refresh=1}"