use SNMP::Trap;
  use My::SNMPDevice;  # A subclass of Class::SNMP

  my $trap = SNMP::Trap->parse_snmptrapd_from_stdin();
  my $obj_trap = My::SNMPDevice->parse_trap($trap); # expects SNMP::Trap
  # $obj_trap isa Class::SNMP::Trap + My::SNMPDevice::Trap::<name>

  my $success = $obj_trap->dispatch({
      alarmWarning   => sub { 1 };
      _namer         => 'trap_%s',
      _default       => \&trap_unhandled,
  });
  if (! $success) {
      print "Couldn't dispatch for trap:\n" . $obj_trap->describe;
  }

  sub trap_alarmCritical {
      my ($trap) = @_;
      print $trap->hostname . " is critical: " . $trap->alarmInformation . "\n";
  }