https://travis-ci.org/github/bitcoin/bitcoin/jobs/679885530#L8791
{
    auto result = WITH_LOCK(g_loading_wallet_mutex, return g_loading_wallet_set.insert(name));
    if (!result.second) {
        error = Untranslated("Wallet already being loading.");
        status = DatabaseStatus::FAILED_LOAD;
        return nullptr;
    }
    auto wallet = LoadWalletInternal(chain, name, load_on_start, options, status, error, warnings);
    WITH_LOCK(g_loading_wallet_mutex, g_loading_wallet_set.erase(result.first));
    return wallet;
}
std::shared_ptr<CWallet> CreateWallet(interfaces::Chain& chain, const std::string& name, Optional<bool> load_on_start, DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error, std::vector<bilingual_str>& warnings)