How to create a private method in Perl.

PrivateMethod.pm

#!/usr/bin/perl

# It looks like magic, but in fact, it's mere random number.
package Magic;

use strict;
use warnings;

sub new {
  my $pkg = shift;
  bless {
    x => shift,
  }, $pkg;
}

# private Method, but everybody can access.
sub _castSpell {
  return int(rand(10));
}

# private Method, and nobody can access.
my $secret_method = sub{
  return int(rand(10));
};

# x is dummy value.
sub getX {
  my $self = shift;
  return $self->{x};
}

# Magic is mere random number.
sub getMagicNum {
  my $self = shift;
#  return $self->_castSpell();
  return $self->$secret_method;
}

1;