<?php
    interface a
    {
        public function foo();
    }

    interface b extends a
    {
        public function baz(Baz $baz);
    }

    /**
    This will work
     */
    class c implements b
    {
        public function foo()
        {
        }

        public function baz(Baz $baz)
        {
        }
    }

    /**
    This will not work and result in a fatal error
     */
    class d implements d
    {
        public function foo()
        {
        }

        public function baz(Baz $baz)
        {
        }
    }
?>