binapi: Failed to get markets data

Hi, I try to replace mini_tickers with markets in the examples/websockets/main.cpp. Then I got the assert failed.

ws_test: src/websocket.cpp:302: binapi::ws::websockets::impl::start_channel(const char*, const char*, F) [with F = std::function<bool(const char*, int, std::__cxx11::basic_string<char>, binapi::ws::markets_tickers_t)>; binapi::ws::websockets::handle = void*]::<lambda(const char*, int, std::string, const char*, std::size_t)>: Assertion `json.is_valid()’ failed.

Could you have a look at this. Thank you for your time and looking forward to your reply.