Test: Initial version of modem tests

esp_modem/include/cxx_include/esp_modem_dce.hpp

@@ -58,9 +58,10 @@ public:
         return dte->command(command, std::move(got_line), time_ms);
     }
 
-protected:
     bool set_mode(modem_mode m) { return mode.set(dte.get(), module.get(), netif, m); }
 
+protected:
+
 
     std::shared_ptr<DTE> dte;
     std::shared_ptr<SpecificModule> module;