package Foo;

sub new {
   my $class = shift;
   my $self = {
      foo => 'bar',
      baz => 'qux',
   };
   return bless $self, $class;
}

# 'private' method
sub _get_foo {
   my $self = shift;
   return $self->{foo};
}

# 'public' method
sub get_foo {
   my $self = shift;
   return $self->_get_foo();
}

##</code><code>##

# 'private' has to change
sub _get_foo {
	my $self = shift;
	return $self->{bar};
}

# but 'public' doesn't
sub get_foo {
	my $self = shift;
	return $self->_get_foo();
}

##</code><code>##

sub get_foo {
   my $self = shift;
   carp "get_foo() is deprecated, use get_bar()";
   return _get_bar();
}

sub get_bar {
   my $self = shift;
   return $self->_get_bar();
}