{
   local %INC;
   delete $INC{YAML.pm};      # make sure YAML isn't loaded
   $INC{'YAML/Syck.pm'} = 1;  # fake loading of YAML::Syck
   sub YAML::Syck::import { die }
   
   require My::Module;
   ok( $INC{'YAML.pm'}, 'YAML loaded when YAML::Syck not present' );
}