tween engine basic

[game2d]

getting a error on "aurelienribon" 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.