private:
	void epsilon_closure() {
		eps_closure.insert(this);
		stack <State*> states_stack;
		states_stack.push(this);
		while (!states_stack.empty()) {
			State* curr_state = states_stack.top();
			states_stack.pop();
			map<char, vector<State*> >::iterator iter = transitions.begin();
			if(iter != transitions.end())
				for (State* s : iter->second)
					eps_closure.insert(s->get_epsilon_closure().begin(), s->get_epsilon_closure().end());
		}
	}



};