package com.example.tests;

import org.testng.annotations.AfterTest;
import org.testng.annotations.BeforeTest;
import com.example.fw.ApplicationManager;

public class TestBase {
	
	public ApplicationManager app;

	@BeforeTest
	public void setUp() throws Exception {
		app = new ApplicationManager();
	  }
	
	@AfterTest
	public void tearDown() throws Exception {
		app.stop();
	  }

}

package com.example.tests;

import org.testng.annotations.AfterTest;
import org.testng.annotations.BeforeTest;
import com.example.fw.ApplicationManager;

public class TestBase {
	
	public static ApplicationManager app;

	@BeforeTest
	public void setUp() throws Exception {
		app = new ApplicationManager();
	  }
	
	@AfterTest
	public void tearDown() throws Exception {
		app.stop();
	  }

}

Define app link as static
Define app link as static