Result: TO_JSON: include simplified wing and replacement / replaced refs

	my ($self) = @_;

	my %copy = %{$self};

	delete $copy{arrival_wings};

	delete $copy{departure_wings};

	delete $copy{realtime_xml};

	delete $copy{replaced_by};

	delete $copy{replacement_for};

	delete $copy{strptime_obj};

	for my $ref_key (

		qw(arrival_wings departure_wings replaced_by replacement_for))

	{

		delete $copy{$ref_key};

		for my $train_ref ( @{ $self->{$ref_key} // [] } ) {

			push(

				@{ $copy{$ref_key} },

				{

					raw_id   => $train_ref->raw_id,

					train    => $train_ref->train,

					train_no => $train_ref->train_no,

					type     => $train_ref->type,

				}

			);

		}

	}

	delete $copy{wing_of};

	if ( my $train_ref = $self->wing_of ) {

		$copy{wing_of} = {

			raw_id   => $train_ref->raw_id,

			train    => $train_ref->train,

			train_no => $train_ref->train_no,

			type     => $train_ref->type,

		};

	}

	for my $datetime_key (

		qw(arrival departure sched_arrival sched_departure start datetime))