use strict;
use warnings;

package Foo;

sub new {
    my $class = shift;
    
    return bless {}, $class;
}

sub bar {
    my $self = shift;
    
    $self->baz;
    
    return 1;
}

sub baz {
    die;
}

1;

##</code><code>##

use strict;
use warnings;

use Foo;

use Test::MockObject::Extends;

my $foo = Foo->new();
my $mock_foo = Test::MockObject::Extends->new( $foo );

$mock_foo->mock('baz',sub { 1 });

$mock_foo->bar;