package MyInterfaceTo::The::Real::Module
use InterfaceModule ("The::Real::Module");
# InterfaceModule will handle method calls that fall
# through, i.e. a bit like Class::MethodMaker

# That would be all coding needed, as long as there 
# are no interface changes. When something changes, just 
# drop in a sub:
sub get_some_data {
   # Changed from param list to named params
   my $self = shift;
   my %param;
   $param{'shoe_size'} = shift;
   $param{'shoe_color'} = shift;
   $param{'shoe_type'} = shift;
   $self->object_slot->get_some_data(%param);
   }
1;