https://github.com/bitcoin/bitcoin/commit/2b781ad66e34000037f589c71366c203255ed058#r83655059
break;
        default:
            to[i] = from[i];
            break;
        }
    }
    return to;
}
/**
 * Decode an I2P-style Base64 string.
 * @param[in] i2p_b64 I2P-style Base64 string.
 * @return decoded `i2p_b64`
 * @throw std::runtime_error if decoding fails
 */
static Binary DecodeI2PBase64(const std::string& i2p_b64)
{
    const std::string& std_b64 = SwapBase64(i2p_b64);
    auto decoded = DecodeBase64(std_b64);
    if (!decoded) {
        throw std::runtime_error(strprintf("Cannot decode Base64: \"%s\"", i2p_b64));
    }
    return std::move(*decoded);
}
/**
 * Derive the .b32.i2p address of an I2P destination (binary).
 * @param[in] dest I2P destination.
 * @return the address that corresponds to `dest`
 * @throw std::runtime_error if conversion fails
 */
static CNetAddr DestBinToAddr(const Binary& dest)