sub agent_handler {
    # ...
    my $wheel = new POE::Wheel::ReadWrite(...);
    $heap->{wheel}->{$wheel->ID} = $wheel;
    $wheel->put("Greetings from MyServer version 1.0");
    # ...
  }

##</code><code>##

  sub agent_handler {
    # ...
    $heap->{wheel}->{$wheel->ID} = $wheel;
    $heap->{socket}->{$wheel->ID} = $socket;
    # ...
  }

  sub agent_error {
    # ...
    delete $heap->{wheel}->{$wheel_id};
    delete $heap->{socket}->{$wheel_id};
  }

##</code><code>##

  $heap->{$wheel->ID} =
    { wheel  => $wheel,
      socket => $socket,
      foo    => $foo,
    };

##</code><code>##

  delete $heap->{$wheel_id};