PropertyA triggers Event1(a), Event3(b)
    PropertyB # triggers no events
    PropertyC triggers Event3(c)
    ...

##</code><code>##

    Property  Event
              1 2 3 4 ...
    ========  ===========
       A      a   b
       B
       C          c
      ...
    
##</code><code>##

    my $property_type_events = {
        Property::A => [ handler { Event::E1->new(@_) } 'a'
                       , handler { Event::E3->new(@_) } 'b' ]
        Property::B => [ ],
        Property::C => [ handler { Event::E3->new(@_) } 'c' ], 
        ...
    };

##</code><code>##

    sub handler(&@) {
        my ($event_ctor, @args) = @_;
        return sub {
            my $event = $event_ctor->(@args);
            return $event->trigger(@_);
        };
    }

##</code><code>##

    sub handle_widget_insertion_events($) {
        my ($widget) = @_;
        for my $property ($widget->get_properties) {
            my $handlers = $property_type_events{ ref($property) };
            next unless $handlers;
            for my $handler (@$handlers) {
                my $rc = $handler->( "pass trigger args here" );
                # do something with result code $rc
            }
        }
    }