Useless use of private variable in void context at appendhashref.pl line 18.
Before $VAR1 = {
          'two' => 'second',
          'one' => 'first'
        };
After $VAR1 = {
          'four' => 'forth',
          'three' => 'third'
        };
Use of uninitialized value in string eq at appendhashref.pl line 21.
not ok 1 - one
#   Failed test 'one'
#   at appendhashref.pl line 21.
Use of uninitialized value in string eq at appendhashref.pl line 22.
not ok 2 - two
#   Failed test 'two'
#   at appendhashref.pl line 22.
ok 3 - three
ok 4 - four
1..4
# Looks like you failed 2 tests of 4.