Merge "Test that if an RA sets the same prefix as DNS, nothing happens." am:...

        expectNat64PrefixChange(callback, mCellNetworkAgent, pref64FromDns);

        inOrder.verify(mMockNetd).clatdStart(iface, pref64FromDns.toString());

        // If the RA prefix reappears, clatd is restarted and prefix discovery is stopped.

        // If an RA advertises the same prefix that was discovered by DNS, nothing happens: prefix

        // discovery is not stopped, and there are no callbacks.

        lp.setNat64Prefix(pref64FromDns);

        mCellNetworkAgent.sendLinkProperties(lp);

        callback.assertNoCallback();

        inOrder.verify(mMockNetd, never()).clatdStop(iface);

        inOrder.verify(mMockNetd, never()).clatdStart(eq(iface), anyString());

        inOrder.verify(mMockDnsResolver, never()).stopPrefix64Discovery(netId);

        inOrder.verify(mMockDnsResolver, never()).startPrefix64Discovery(netId);

        // If the RA is later withdrawn, nothing happens again.

        lp.setNat64Prefix(null);

        mCellNetworkAgent.sendLinkProperties(lp);

        callback.assertNoCallback();

        inOrder.verify(mMockNetd, never()).clatdStop(iface);

        inOrder.verify(mMockNetd, never()).clatdStart(eq(iface), anyString());

        inOrder.verify(mMockDnsResolver, never()).stopPrefix64Discovery(netId);

        inOrder.verify(mMockDnsResolver, never()).startPrefix64Discovery(netId);

        // If the RA prefix changes, clatd is restarted and prefix discovery is stopped.

        lp.setNat64Prefix(pref64FromRa);

        mCellNetworkAgent.sendLinkProperties(lp);

        expectNat64PrefixChange(callback, mCellNetworkAgent, pref64FromRa);

        inOrder.verify(mMockNetd).clatdStop(iface);

        inOrder.verify(mMockDnsResolver).stopPrefix64Discovery(netId);

        // Stopping prefix discovery results in a prefix removed notification.

        mService.mNetdEventCallback.onNat64PrefixEvent(netId, false /* added */,

                pref64FromDnsStr, 96);

        inOrder.verify(mMockNetd).clatdStart(iface, pref64FromRa.toString());

        inOrder.verify(mMockDnsResolver, never()).startPrefix64Discovery(netId);