package MyTest::Base;
use strict;
no autovivification;

sub new {
	bless {}, shift;
}

sub  chkAccessRight {
	my $self = shift;
	print "Base chkAccessRight @_$/";
	my ( $usr, $service ) = @_ ;
	return 1;
}

sub tryAccess {
	my $self = shift;
	print "Base tryAccess @_$/";
	my ( $usr, $service ) = @_ ;
	return $self -> chkAccessRight (  $usr => $service ) ;
}

1;

##</code><code>##

package MyTest::Lite;
no autovivification;
use parent 'MyTest::Base';
use strict;

sub new {
	my $self = shift;
	my $parent = $self -> SUPER::new ;
	return bless { Parent => $parent, @_} , $self;
}

sub chkAccessRight {
	my $self = shift;
	print "Lite chkAccessRight @_$/";	
	if ( $self -> {Usr} ) {
		return $self->{Parent}->SUPER::chkAccessRight ( $self->{Usr} , shift ) ;
	}
	else {
		return $self->{Parent}->SUPER::chkAccessRight ( @_ ) ;
	}	
	return 1;
}

sub tryAccess {
	my $self = shift;
	print "Lite tryAccess @_$/";
	if ( $self -> {Usr} ) {
		return $self->{Parent}->SUPER::tryAccess ( $self->{Usr} , shift ) ;
	}
	else {
		return $self->{Parent}->SUPER::tryAccess ( @_) ;
	}	
}

1;

##</code><code>##

use MyTest::Lite;
use strict;

my $lite = new MyTest::Lite (  Usr => 'guest') ;

$lite -> chkAccessRight ( "app2" ) ;
print "======================$/";
$lite -> tryAccess (  "app1"  );

##</code><code>##

Can't call method "SUPER::chkAccessRight" on an undefined value at MyTest/Lite.pm line 19.
Lite chkAccessRight app2
Base chkAccessRight guest app2
======================
Lite tryAccess app1
Base tryAccess guest app1
Lite chkAccessRight guest app1