Eu adiciono primeiro fragmento assim

            FragmentManager fm = SliderActivity.this
                    .getSupportFragmentManager();
            FragmentTransaction ft = fm.beginTransaction();
            Fragment fragment = null;
            fragment = new HomeFragment();
            ft.add(R.id.content_fragment, fragment, "Home");
                ft.addToBackStack("Home");
                ft.commit();

e segundo fragmento como

            FragmentManager fm = SliderActivity.this
                    .getSupportFragmentManager();
            FragmentTransaction ft = fm.beginTransaction();
            Fragment fragment = null;
            fragment = new HomeFragment();
            ft.add(R.id.content_fragment, fragment, "About");
            ft.addToBackStack("About");
            ft.commit();

Minha pergunta é: se eu pressionar o botão voltar de AboutFragment (Second), como chamar um método de HomeFragment (First)

            onResume() is not fired which is creating problem