New to automation. Help is greatly needed

Anybody could help me with following code

Why i am getting NullPointerException?

Error: Null pointer access: The variable driver can only be null at this location

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.testng.annotations.Test;
import common.controls.PageVerified;


public class Google extends PageVerified{
        PageVerified PgVerif = new PageVerified();
        WebDriver driver = new ChromeDriver();
    
        
        @Test
            public void Login() throws Exception{
            driver.manage().window().maximize();
            driver.get("https:Google.com");
            driver.findElement(By.xpath("//*[@id='lst-ib']")).sendKeys("Test");
            Thread.sleep(2000);
            driver.findElement(By.className("lsb")).click();
            PgVerif.Verify();
            String a = driver.getTitle();
            System.out.println(a);
            driver.findElement(By.xpath("//*[@id='lst-ib']")).clear();
            driver.findElement(By.xpath("//*[@id='lst-ib']")).sendKeys("Test");
            Thread.sleep(2000);
            driver.findElement(By.className("sbico-c")).click();
            String b = driver.getTitle();
            System.out.println(b);
            
            driver.close();
        }
            
        

Following is another class that i am calling where i get error and it is in seperate Pacakage than the above

package common.controls;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;

public class PageVerified 
{
    public String Verify()
        {
            WebDriver driver = null ;
            String pagetitle = driver.findElement(By.xpath("//*[@id='gb_70']")).getText();
                if(pagetitle != null)
                {
                    System.out.println(pagetitle + "Verified Successfully"  );
                    return pagetitle;
                }
                else
                {
                    System.out.println("Error::Not Verified");
                }
                return null;
                        }   
}