code: private void initializeFloatingActionButton() {
          floatingActionButton = findViewById(R.id.floating_action_button);
  
          if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
              floatingActionButton.show();
              floatingActionButton.setOnClickListener(createFloatingActionButtonListener());
          } else {
              floatingActionButton.hide();
          }
      }
docs: Initializes the floating action button, which allows to show an alert dialog using a circle
  reveal animation.