{
  package Parent;
  use Private;
  sub private_method { is_private; print "Private method calleed OK.\n" }
  sub public_method { $_[0]->private_method }
}

{
  package Child;
  use base 'Parent';
  sub child_calling_private { $_[0]->private_method }
  sub child_calling_public { $_[0]->public_method }
}

package main;

print "\nBase class: call private method directly:\n";
eval {  Parent->private_method }; $@ and print $@;

print "\nBase class: call public method that calls private method:\n";
eval {  Parent->public_method; }; $@ and print $@;

print "\nDerived class: call parent's private method directly:\n";
eval {  Child->private_method }; $@ and print $@;

print "\nDerived class: call parent's public method that calls private method:\n";
eval {  Child->public_method; }; $@ and print $@;

print "\nDerived class: call method that calls parent's private method:\n";
eval { Child->child_calling_private; }; $@ and print $@;

print "\nDerived class: call method that calls parent's public method:\n";
eval { Child->child_calling_public; }; $@ and print $@;