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;

}