NYI: CLEANUP: remove this arg?
the request message for which this response was generated

the major version

the minor version

the status code of the response

the reason-phrase of the response

the header fields

the body of the response

String representation of the message header

String representation of the whole message, i.e. header and body

get the body of the message as a String

the whole message as a sequence of bytes

the start line of the message, for a response this is also called status line

the status line of the response message

create an http response using a default values

request_message => nil
major => 1
minor => 1
reason_phrase via status code from reason phrases map