`bitcoin.conf`:
```
...
testnet=1
# [wallets]
test.wallet=test_alpha
test.wallet=alpha_wallet
test.wallet=none
...
```

Run bitcoin client.

`debug.log`:
```
...
2019-02-03T13:09:23Z Using wallet directory /home/hebasto/.bitcoin/testnet3/wallets
2019-02-03T13:09:23Z init message: Verifying wallet(s)...
2019-02-03T13:09:23Z Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2019-02-03T13:09:23Z Using wallet wallet.dat
2019-02-03T13:09:23Z BerkeleyEnvironment::Open: LogDir=/home/hebasto/.bitcoin/testnet3/wallets/test_alpha/database ErrorFile=/home/hebasto/.bitcoin/testnet3/wallets/test_alpha/db.log
2019-02-03T13:09:23Z Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2019-02-03T13:09:23Z Using wallet wallet.dat
2019-02-03T13:09:23Z BerkeleyEnvironment::Open: LogDir=/home/hebasto/.bitcoin/testnet3/wallets/alpha_wallet/database ErrorFile=/home/hebasto/.bitcoin/testnet3/wallets/alpha_wallet/db.log
2019-02-03T13:09:23Z Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2019-02-03T13:09:23Z Using wallet wallet.dat
2019-02-03T13:09:23Z BerkeleyEnvironment::Open: LogDir=/home/hebasto/.bitcoin/testnet3/wallets/none/database ErrorFile=/home/hebasto/.bitcoin/testnet3/wallets/none/db.log9
...
```

In multi-wallet environment a wallet database file reference (`wallet.dat`) without a wallet name (e.g., `test_alpha`) could be confusing.
{
    if (!fDbEnvInit)
        return;
    fDbEnvInit = false;
    for (auto& db : m_databases) {
        auto count = mapFileUseCount.find(db.first);
        assert(count == mapFileUseCount.end() || count->second == 0);
        BerkeleyDatabase& database = db.second.get();
        if (database.m_db) {
            database.m_db->close(0);
            database.m_db.reset();
        }
    }
    int ret = dbenv->close(0);
    if (ret != 0)
        LogPrintf("BerkeleyEnvironment::Close: Error %d closing database environment: %s\n", ret, DbEnv::strerror(ret));
    if (!fMockDb)
        DbEnv((u_int32_t)0).remove(strPath.c_str(), 0);
}
void BerkeleyEnvironment::Reset()