Mocking class and callbacks funcitons in 'anonymous namespace'

[avinashgoud13]

FileName: MyClass.h

class MyClass {
public: 
	MyClass();

	void Start();
}

Filename: MyClass.cpp

namespace {
	class ServerState() {
	....
	...
	};

ServerState _state;

void readCallBack(void *server){
	......
	}
}

Mocking MyClass::Start()

MyClass::MyClass(){
	// constructor of my class
	_state = NULL;
	_server = NULL;
}
void MyClass::Start() {
	 if (_state != NULL) {
	   // do something
	  return;
	}
	_server = new Server (readCallBack);
	return;
 }

I am getting error, saying ServerState (anonymous namespace)::_state;
Also, readCallBack is undeclared.