Set the Request data to data. This is ignored
by all handlers except HTTP handlers -- and there it should be an
application/x-www-form-encoded buffer, and will change the
request to be POST rather than GET.
Return a string indicating the HTTP request method. This is only
meaningful for HTTP requests, and currently always takes one of the
values ("GET", "POST").
Add another header to the request. Headers are currently ignored by
all handlers except HTTP handlers, where they are added to the list
of headers sent to the server. Note that there cannot be more than
one header with the same name, and later calls will overwrite
previous calls in case the key collides. Currently, this is
no loss of HTTP functionality, since all headers which have meaning
when used more than once have a (header-specific) way of gaining the
same functionality using only one header.
Prepare the request by connecting to a proxy server. The host
and type will replace those of the instance, and the instance's
selector will be the original URL given in the constructor.
