URI that was passed to $ua->request() method, because we might have
received some redirect responses first.

=back

If a filename cannot be derived from any of these sources, undef is
returned.

=item $r->as_string

=item $r->as_string( $eol )

Returns a textual representation of the response.

=item $r->is_info

=item $r->is_success

=item $r->is_redirect

=item $r->is_error

These methods indicate if the response was informational, successful, a
redirection, or an error.  See L<HTTP::Status> for the meaning of these.

=item $r->error_as_HTML

Returns a string containing a complete HTML document indicating what
error occurred.  This method should only be called when $r->is_error
is TRUE.

=item $r->current_age

Calculates the "current age" of the response as specified by RFC 2616
section 13.2.3.  The age of a response is the time since it was sent
by the origin server.  The returned value is a number representing the
age in seconds.

=item $r->freshness_lifetime

Calculates the "freshness lifetime" of the response as specified by
RFC 2616 section 13.2.4.  The "freshness lifetime" is the length of
time between the generation of a response and its expiration time.
The returned value is a number representing the freshness lifetime in
seconds.

If the response does not contain an "Expires" or a "Cache-Control"
header, then this function will apply some simple heuristic based on
'Last-Modified' to determine a suitable lifetime.

=item $r->is_fresh

Returns TRUE if the response is fresh, based on the values of
freshness_lifetime() and current_age().  If the response is no longer
fresh, then it has to be refetched or revalidated by the origin
server.

=item $r->fresh_until

Returns the time when this entity is no longer fresh.

=back

=head1 SEE ALSO

L<HTTP::Headers>, L<HTTP::Message>, L<HTTP::Status>, L<HTTP::Request>

=head1 COPYRIGHT

Copyright 1995-2004 Gisle Aas.

This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.