Renders the response message.
If a message body is provided, it is appended to the response message
according to RFC 2616, section 4.3; that is,
- If status is either below 200 or 204 or 304, neither a message body
nor a "Content-Length" header field are appended.
- Otherwise, if head is true, a "Content-Length" header field reflecting
msg_body.length is appended but the message body itself is not.
- Otherwise, if head is false, both a "Content-Length" header field
reflecting msg_body.length and the message body itself are appended.
If a message body is not provided, the same is done as for a message
body with a zero length.
Renders the response message. If a message body is provided, it is appended to the response message according to RFC 2616, section 4.3; that is, - If status is either below 200 or 204 or 304, neither a message body nor a "Content-Length" header field are appended. - Otherwise, if head is true, a "Content-Length" header field reflecting msg_body.length is appended but the message body itself is not. - Otherwise, if head is false, both a "Content-Length" header field reflecting msg_body.length and the message body itself are appended.
If a message body is not provided, the same is done as for a message body with a zero length.