@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        presenter = MaterialPresenter.getInstance();                // get the instance of our presenter
        
        // ATTACH the activity to the presenter telling it the id of the MaterialToolbar and the view holding the Fragments
        presenter.attachActivity(this, R.id.main_toolbar, R.id.fragmentContainer);  
        // Only if the fragment container has no fragment, we tell the MaterialPresenter to navigate to a new Fragment instance
        // This will assure the right behaviour during screen rotation and other configuration changes
        if (getFragmentManager().findFragmentById(R.id.fragmentContainer) == null) {
            presenter.navigateTo(new MyAwesomeFragment());
        }
    }
        

    @Override
    protected void onDestroy() {
        super.onDestroy();
        presenter.detachActivity();
    }

    @Override
    public void onBackPressed(){
        if(!presenter.onBackPressed()) super.onBackPressed();
    }

public class MyAwesomeFragment extends Fragment implements MaterialToolbarSupplier {
  @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      // [...] infalte your fragment view
      
      // This is your time to create your MaterialToolbarContent and instantiate the views.
      toolbarContent = new MaterialToolbarContent(getActivity(), R.layout.my_awesome_toolbar);
      // Tell the presenter to set the MaterialToolbarContent of this Fragment.
      presenter.getToolbar().setContent(toolbarContent);
      // Instantiate all views
      Button myAwesomeButton = toolbarContent.findViewById(R.id.myAwesomeButton);
      myAwesomeButton.findViewById(R.id.myAwesomeButton).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                presenter.navigateTo(new OtherFragment());  // We can use the presenter this Fragment to navigate to others.
            }
        });
      // [...]
      return view;
    }
}

    @Override
    public void setPresenter(MaterialPresenter presenter) {
        // get the presenter instance, you can use it later for navigate to children Fragments.
        this.presenter = presenter;
    }
    
    @Override
    public MaterialToolbarContent getToolbarContent() {
        // This will allow the presenter to set the MaterialToolbarContent when user navigates back to 
        // this Fragment or during configuration changes
        return toolbarContent;
    }