ow the servlet container to use a persistent connection to return its response to the client,
 improving performance. The content length is automatically set if the entire response fits inside the response
 buffer.

 <p>
 When using HTTP 1.1 chunked encoding (which means that the response has a Transfer-Encoding header), do not set the
 Content-Length header.

 <p>
 This method does not need to be either safe or idempotent. Operations requested through POST can have side effects
 for which the user can be h