public static L3ModificationInstruction decNwTtl() {
        return new ModTtlInstruction(L3SubType.DEC_TTL);
    }
@Test
    public void testDecNwTtlOutMethod() {
        final Instruction instruction = Instructions.decNwTtl();
        final L3ModificationInstruction.ModTtlInstruction modTtlInstruction =
                checkAndConvert(instruction,
                                Instruction.Type.L3MODIFICATION,
                                L3ModificationInstruction.ModTtlInstruction.class);
        assertThat(modTtlInstruction.subtype(),
                   is(L3ModificationInstruction.L3SubType.DEC_TTL));
    }