package _Initializable;

sub new {
   my ($self,$args);
   my $private_stuff = "private";
   my $class_data = { do stuff here 
                   "class_data" => $private_stuff};
   bless $class_data, ref($class)||$class;
   $self->_init($args); # pass them back to the calling mod
}


##</code><code>##

use _Initializable;
package Caller;

# suck "new" in from _Initializable, along with our
# data private to object Caller when we call 
# $foo=Caller->new($arg) elsewhere

@Caller::ISA = qw(_Initializable); 

# no "new" constructor in any of our stuff... we use _init
# to do "construction"
# now so that we inherit from _initializable
# obviously if you want to provide a class method in
# _Initializable for the private data, that wouldn't be too
# difficult.  

sub _init {

  my ($self,$arg) = @_;
  do other stuph
  return $self;

}