\n"; } } class regular implements pump { function get_gas() { echo "chug..cough..chug..\n
\n"; } } class mercedes { function infuse_gas(premium $pump) { echo "mercedes: "; $pump->get_gas(); } } class pinto { function infuse_gas(pump $pump) { echo "pinto: "; $pump->get_gas(); } } $pinto = new pinto; $pinto->infuse_gas(new premium); $pinto->infuse_gas(new regular); $mercedes = new mercedes; $mercedes->infuse_gas(new premium); $mercedes->infuse_gas(new regular); ?>