        package Pinger;
        use Moose;
        extends 'Reflex::Base';
use Reflex::Trait::Observed;

        observes echoer => (
                isa     => 'Echoer',
                default => sub { Echoer->new() },
        );

        sub BUILD {
                my $self = shift;
                $self->echoer->ping();
        }

        sub on_echoer_pong {
                my $self = shift;
                print "Pinger got echoer's pong!\n";
                $self->echoer->ping();
        }
