https://travis-ci.org/github/bitcoin/bitcoin/jobs/680452476#L6107
{
    return RPCHelpMan{"prioritisetransaction",
                "Accepts the transaction into mined blocks at a higher (or lower) priority\n",
                {
                    {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id."},
                    {"dummy", RPCArg::Type::NUM, RPCArg::Optional::OMITTED_NAMED_ARG, "API-Compatibility for previous API. Must be zero or null.\n"
            "                  DEPRECATED. For forward compatibility use named arguments and omit this parameter."},
                    {"fee_delta", RPCArg::Type::NUM, RPCArg::Optional::NO, "The fee value (in satoshis) to add (or subtract, if negative).\n"
            "                  Note, that this value is not a fee rate. It is a value to modify absolute fee of the TX.\n"
            "                  The fee is not actually paid, only the algorithm for selecting transactions into a block\n"
            "                  considers the transaction as it would have paid a higher (or lower) fee."},
                },
                RPCResult{
                    RPCResult::Type::BOOL, "", "Returns true"},
                RPCExamples{
                    HelpExampleCli("prioritisetransaction", "\"txid\" 0.0 10000")
            + HelpExampleRpc("prioritisetransaction", "\"txid\", 0.0, 10000")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    LOCK(cs_main);
    uint256 hash(ParseHashV(request.params[0], "txid"));
    CAmount nAmount = request.params[2].get_int64();
    if (!(request.params[1].isNull() || request.params[1].get_real() == 0)) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Priority is no longer supported, dummy argument to prioritisetransaction must be 0.");
    }