Handling postback for PoCo::TCP::Server

I'm trying to create a postback event  for my server .......but for some
reason I'm not seeing the $session->postback('client_output') get called.  I
want to wait to receive a response from the $kernel->post before I respond
back to the client with the returned result.

I think my syntax must be wrong in the post string order but I wasn't sure
how to change it to send args and the postback correctly

$self->{server}= POE::Component::Server::TCP->new(
          ..........
          # Handle client requests here.
          ClientInput => sub {
                 my ($kernel, $heap, $session, $list) = @_[KERNEL, HEAP,
SESSION, ARG0];
                .............
                $kernel->post( $session_alias, $event, [$alias, $params],
$session->postback('client_output') );

                #$heap->{client}->put(\%response);
          },
          InlineStates => {
            client_output => sub {
              my ($heap, $response) = @_[HEAP, ARG1];
              print STDERR "MADE IT TO THE CALLBACK\n";
              $heap->{client}->put($response->[0])
                if defined $heap->{client}
                  # that is, if $heap->{client} is still connected
              }
          },

          SessionParams => [ options => { debug => 1, trace => 1 } ],

          ClientDisconnected => sub {
                my $kernel = $_[KERNEL];
                print STDERR "THE CLIENT DISCONNECTED\n";

          },

    );