use 5.014;

package OldObj {
    sub new {bless {}, __PACKAGE__}
    sub test {
        print "You're still using the old object!\n";
    }
};

package NewObj {
    sub new {bless {}, __PACKAGE__}
    sub test {
        print "Yuppie! This is the new object!\n";
    }
};


my $keep   = OldObj->new();   # object_1
my $change = OldObj->new();   # object_2

my $ref1 = $change;           # points to object_2
my $ref2 = $ref1;             # points to object_2


# object_2 needs to be replaced with another object,
# but the object_1 should still be ref 'OldObj'

# ... code needs to be added here ...


say ref($ref1);    # should print 'NewObj'
$ref2->test();     # should go to NewObj::test()
$keep->test();     # should go to OldObj::test()