code: private Drawable createStateListBackgroundDrawable() {
          StateListDrawable drawable = new StateListDrawable();
  
          if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
              drawable.addState(new int[]{android.R.attr.state_enabled, android.R.attr.state_pressed},
                      createPressedBackgroundDrawable());
          }
  
          drawable.addState(new int[]{android.R.attr.state_enabled, android.R.attr.state_activated},
                  createActivatedBackgroundDrawable());
          drawable.addState(new int[]{android.R.attr.state_enabled},
                  createBackgroundDrawable(getColor()));
          drawable.addState(new int[]{}, createDisabledBackgroundDrawable());
          return drawable;
      }
docs: Creates and returns a state list drawable, which can be used as the floating action button
  background and adapts the background color depending on the button's current state.
  
  @return The drawable, which has been created, as an instance of the class {@link Drawable}