Bod:

The second function, access_token, is fetching a value from the object referenced by $self, so it's pretty straightforward.

The request function is a *little* more subtle: As you notice, it calls the access_token function, but the result from that call is treated as a reference to an object that has a request function. Note that the object referenced by access_token is *not* necessarily the same class or object found in the request function you posted. So in order to understand what's happening, you'll need to figure out where the access_token member in the object is being set, so you can figure out what sort of object is being accessed.

Sometimes when tracking through the code is a bit annoying, I'll do something like a quick edit of the module:

$ # make a copy of the module so I don't mess it up
$ cp /home/shoples1/perl5/lib/perl5/LWP/Authen/OAuth2.pm foo.pm
$ vi /home/shoples1/perl5/lib/perl5/LWP/Authen/OAuth2.pm
 . . . edit the request subroutine to look like:
sub request {
    my ($self, $request, @rest) = @_;
    use Data::Dumper;
    my $temp = $self->access_token;
    print "access token is: ", Dumper($temp), "\n";
    return $temp->request($self, $request, @rest);
}
$ # run the project so I can see what I'm looking for
$ perl t.pl
blah, blah, blah
access token is:$VAR1 = bless( {
                 'baz' => 'boom',
                 'foo' => 'bar'
               }, 'Barsoom!' );

blah, blah, blah
$ # put things back so I don't cause more problems for myself
$ cp foo.pm /home/shoples1/perl5/lib/perl5/LWP/Authen/OAuth2.pm
[download]

Hope this helps!

...roboticus

When your only tool is a hammer, all problems look like your thumb.