my $obj = new->( arg => 23); 

$obj->run();  # run will use 23

# OR INSTEAD:

my $obj = new->( configuration => file ); # this will load [12, 23, 15] into $obj->{ container }

$obj->run_all();

sub run_all{
   my $self = shift;
   foreach my $it ( @{$obj->{ container }} ){
       my $new_obj = ref($self)->new($it);
       $new_obj->run;
   }
}
# update: i had Class instead of new in the above: corrected