https://github.com/bitcoin/bitcoin/issues/15555#issuecomment-479346264
{
    if (jsonRequest.fHelp || jsonRequest.params.size() > 1)
        throw std::runtime_error(
            RPCHelpMan{"help",
                "\nList all commands, or get help for a specified command.\n",
                {
                    {"command", RPCArg::Type::STR,  "all commands", "The command to get help on"},
                },
                RPCResult{
            "\"text\"     (string) The help text\n"
                },
                RPCExamples{""},
            }.ToString()
        );
    std::string strCommand;
    if (jsonRequest.params.size() > 0)
        strCommand = jsonRequest.params[0].get_str();
    return tableRPC.help(strCommand, jsonRequest);
}
UniValue stop(const JSONRPCRequest& jsonRequest)