테스트 메서드마다 AppConfig 인스턴스를 만들어줘야하나요?

package hello.core.member;

import hello.core.AppConfig;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

public class MemberServiceTest {

    AppConfig appConfig = new AppConfig();
    MemberService memberService = appConfig.memberService();
    
    @BeforeEach
    public void beforeEach() {
    }

    @Test
    void join() {
        // given
        Member member = new Member(1L, "memberA", Grade.VIP);

        // when
        memberService.join(member);
        Member findMember = memberService.findMember(1L);

        //then
        Assertions.assertThat(member).isEqualTo(findMember);
    }
}

beforeEach에서 인스턴스 매번 안만들고 한번 만들어서 써도 되지 않나요?