tween engine basic

[game2d]

getting a error on "aurelienri bon" and "TweenAccessor< Sprite>"

error: TweenAccessor cannot be resolved to a type

package com.me.mygdxgame.tween;

import aurelienribon.tweenengine.TweenAccessor;
import com.badlogic.gdx.graphics.g2d.Sprite;


public class spriteAccesor implements TweenAccessor<Sprite> {

    
    @Override
    public int getValues(Sprite target, int tweenType, float[] returnValues) {
	}

   @Override
   public void setValues(Sprite target, int tweenType, float[] newValues) {

	}

}

do i need to download to use libaries? if yes, than how can i do this.