Оправданно ли использование static в моем случае?

#include<iostream>
#include<functional>
#include<map>
#include<string>

using namespace std;

class Client
{
  map<string, function<void()>> functions;
  void printThis()
  {
    cout << "this: " << this << endl;
  }

public:
  Client()
  {
    functions["printThis"] = [this]{ printThis(); };
  }

  void commandListener(const string& command)
  {
    if(auto it{ functions.find(command) }; it != functions.end())
    {
      it->second();
    }
    else
    {
      cout << "This command does not exist\n"
           << "Add this blank command? (y/n) ";
      if(cin.get() == 'y')
      {
        addCommand(command);
        cout << "Ok!" << endl;
      }
    }
  }

  void addCommand(const string& cmd, function<void()>&& fn = {})
  {
    if(functions.count(cmd) == 0)
    {
      functions[cmd] = fn;
    }
  }
};


int main()
{
  Client cl;
  cl.addCommand("printNumber42", [](){ cout << 42 << endl; });
  cl.addCommand("printTextText", [](){ cout << "Text" << endl; });


  cl.commandListener("printNumber42");
  cl.commandListener("printTextText");
  cl.commandListener("blank");
  cl.commandListener("printThis");

  system("pause");
}