Specifically, it adds an address into the wallet.

Easy to test now thanks to https://github.com/bitcoin/bitcoin/pull/14410
```
diff --git a/test/functional/wallet_importmulti.py b/test/functional/wallet_importmulti.py
index 9ba6860..bff37b2 100755
--- a/test/functional/wallet_importmulti.py
+++ b/test/functional/wallet_importmulti.py
@@ -95,6 +95,7 @@ class ImportMultiTest(BitcoinTestFramework):
         assert_equal(address_assert['iswatchonly'], True)
         assert_equal(address_assert['ismine'], False)
         assert_equal(address_assert['timestamp'], timestamp)
+        assert_equal(address_assert['ischange'], True)
 
         # ScriptPubKey + internal + label
         self.log.info("Should not allow a label to be specified when internal is true")
```

std::set<CScriptID> scripts = pwallet->GetCScripts();
    
    
    std::vector<std::pair<int64_t, CKeyID> > vKeyBirth;
    for (const auto& entry : mapKeyBirth) {
        if (const CKeyID* keyID = boost::get<CKeyID>(&entry.first)) { 
            vKeyBirth.push_back(std::make_pair(entry.second, *keyID));
        }
    }
    mapKeyBirth.clear();
    std::sort(vKeyBirth.begin(), vKeyBirth.end());
    
    file << strprintf("# Wallet dump created by Bitcoin %s\n", CLIENT_BUILD);
    file << strprintf("# * Created on %s\n", FormatISO8601DateTime(GetTime()));
    file << strprintf("# * Best block at time of backup was %i (%s),\n", chainActive.Height(), chainActive.Tip()->GetBlockHash().ToString());
    file << strprintf("#   mined on %s\n", FormatISO8601DateTime(chainActive.Tip()->GetBlockTime()));
    file << "\n";
    
    CKeyID seed_id = pwallet->GetHDChain().seed_id;
    if (!seed_id.IsNull())
    {
        CKey seed;
        if (pwallet->GetKey(seed_id, seed)) {
            CExtKey masterKey;
            masterKey.SetSeed(seed.begin(), seed.size());
            file << "# extended private masterkey: " << EncodeExtKey(masterKey) << "\n\n";
        }
    }
    for (std::vector<std::pair<int64_t, CKeyID> >::const_iterator it = vKeyBirth.begin(); it != vKeyBirth.end(); it++) {
        const CKeyID &keyid = it->second;