pl@nereida:~/LEyapp/examples$ cat attributeprotected.pl
#!/usr/local/bin/perl -w
package SomeClass;
use Attribute::Protected;

sub foo  : Public    { }
sub _bar : Private   { }
sub _baz : Protected { }

sub another {
    my $self = shift;
    $self->foo;               # OK
    $self->_bar;              # OK
    $self->_baz;              # OK
}

sub new {
  bless {}, $_[0]
}

package DerivedClass;
@DerivedClass::ISA = qw(SomeClass);

sub yetanother {
    my $self = shift;
    $self->foo;               # OK
    $self->_bar;              # NG: private method
    $self->_baz;              # OK
}

package main;

my $some = SomeClass->new;
$some->foo;           # OK
print ($some->can('_bar')?"Yes, main can see that SomeClass has a _bar method\n":"no\n");