Function esp_idf_sys::esp_transport_ws_set_subprotocol

pub unsafe extern "C" fn esp_transport_ws_set_subprotocol(
    t: esp_transport_handle_t,
    sub_protocol: *const c_char,
) -> esp_err_t

@brief Set websocket sub protocol header

@param t websocket transport handle @param sub_protocol Sub protocol string

@return - ESP_OK on success - One of the error codes