class TCCCCommonCallback : public ITXCallback {
private:
    NSString* mFunName;
public:
    TCCCCommonCallback(NSString* funName) {
        mFunName = funName;
    }
    ~TCCCCommonCallback() override {
        
    }
    void OnSuccess() override {
      // Succeeded
    }
    
    void OnError(TCCCError error_code, const char *error_message) override {
        std::string copyErrMsg = makeString(error_message);
      // Failed
    }
};
TCCCCommonCallback* startCallCallbackImpl = nullptr;
if (nullptr == startCallCallbackImpl) {
  startCallCallbackImpl = new TCCCCommonCallback(@"startCall");
}
TCCCStartCallParams callParams;
// Phone number for the call
callParams.to = "";
// Initiate a call. Call the login API before initiating a call. tcccSDK->login
tcccSDK->call(callParams, startCallCallbackImpl);
// End the call
tcccSDK->terminate();