@Override
    protected void onRestoreInstanceState(Parcelable state) {
        if (state == null || !state.getClass().equals(CustomState.class)) {
            super.onRestoreInstanceState(state);
            return;
        }

        CustomState customState = (CustomState) state;
        setMin(customState.min);
        setMax(customState.max);
        setProgress(customState.progress, false);
        super.onRestoreInstanceState(customState.getSuperState());
    }
When the {@link DiscreteSeekBar} value changes this method is called
<p>
Subclasses may override this to add functionality around this event
without having to specify a {@link OnProgressChangeListener}
</p>
app/src/main/java/com/duan/musicoco/view/discreteseekbar/DiscreteSeekBar.java