Fedora URI for this object (``info:fedora/foo:###`` form of object pid)

def uri(self):
        "Fedora URI for this object (``info:fedora/foo:###`` form of object pid) "
        use_pid = self.pid
        if callable(use_pid):
            use_pid = self.DUMMY_PID
        return 'info:fedora/' + use_pid