content: package com.bookstore;
  
  import com.bookstore.service.BookstoreService;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.boot.ApplicationRunner;
  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  import org.springframework.context.annotation.Bean;
  
  @SpringBootApplication
  public class MainApplication {
  
      @Autowired
      private BookstoreService bookstoreService;
  
      public static void main(String[] args) {
          SpringApplication.run(MainApplication.class, args);
      }
  
      @Bean
      public ApplicationRunner init() {
          return args -> {
              System.out.println("\n\npersistAuthorWithBooks():");
              bookstoreService.persistAuthorWithBooks();
  
              System.out.println("\n\nfetchBookByTitle():");
              bookstoreService.fetchBookByTitle();
              
              System.out.println("\n\nfetchBookByIsbn():");
              bookstoreService.fetchBookByIsbn();
          };
      }
  }
  