Nullpointer Exception when using the @Before and @After notations in Selenium

Question

When using the ratings @Before and @After, is giving nullpointer error.

Does anyone know what it is?

Follows the code:

import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.openqa.selenium.By;
import org.openqa.selenium.Dimension;
import org.openqa.selenium.Keys;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;

public class TesteAmericanas {

    private WebDriver driver;

    @Before
    public void inicializa() {
        System.setProperty("webdriver.chrome.driver", "/Users/Frederico/Cursos/Selenium WebDriver/chromedriver_win32/chromedriver.exe");
        ChromeOptions options = new ChromeOptions();
        options.addArguments("--disable-notifications");
        WebDriver driver = new ChromeDriver(options);
        driver.manage().window().setSize(new Dimension(1280,720));
        driver.get("https://www.americanas.com.br/");   
    }
    @After
    public void finaliza() {
        driver.close();
    }
@Test
    public void verificaTituloDaPaginaInicial() {
        Assert.assertEquals("Americanas.com - A maior loja. Os menores preços.", driver.getTitle());  
    }
}