Gets a list of all ports on OVS instance.

        This method is corresponding to the following ovs-vsctl command::

            $ ovs-vsctl list-ports <bridge>

def get_port_name_list(self):
        """
        Gets a list of all ports on OVS instance.

        This method is corresponding to the following ovs-vsctl command::

            $ ovs-vsctl list-ports <bridge>
        """
        command = ovs_vsctl.VSCtlCommand('list-ports', (self.br_name, ))
        self.run_command([command])
        return command.result