Why is setScreen broken?

Main.java

package com.my.game;

import com.badlogic.gdx.ApplicationAdapter;

import com.badlogic.gdx.Game;	// This import is reported as unused, but is needed for setScreen?

import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;

public class Main extends ApplicationAdapter {
	public SpriteBatch batch;
	public BitmapFont font;

	@Override
	public void create() {
		batch = new SpriteBatch();
		font = new BitmapFont();

		this.setScreen(new MainMenuScreen(this)); // setScreen isn't found?
	}

	@Override
	public void render(){
		super.render();
	}

	@Override
	public void dispose() {
		batch.dispose();
		font.dispose();
	}
}