I'm trying to create new enemies from their own class. I try to pass World from another class as parameter however when trying to add new body to world it results a nullpointer. Here's the constructor from Enemy-class
public Enemy(float x, float y, World world){
    enemyTexture = new Texture(Gdx.files.internal("ball.bmp"));
    BodyDef myBodyDef = new BodyDef();
    myBodyDef.type = BodyDef.BodyType.DynamicBody;
    myBodyDef.position.set(x, y);
    FixtureDef enemyFixtureDef = new FixtureDef();
    enemyFixtureDef.density     = 1.5f;
    enemyFixtureDef.restitution = 0.1f;
    enemyFixtureDef.friction    = 0.5f;
    CircleShape circleshape = new CircleShape();
    circleshape.setRadius(enemyRadius);
    enemyFixtureDef.shape = circleshape;
    enemyBody = world.createBody(myBodyDef);
    enemyBody.setUserData("enemy");
    enemyBody.createFixture(enemyFixtureDef);
}
 
    