title: JUnit: how to test method which deletes entity (JPA)
body: <p>I have simple crud repository:</p>
  
  <pre><code>public interface BookRepository extends CrudRepository&lt;Book, Long&gt; {
      @Modifying
      @Transactional
      void deleteById(Long id);
  }
  </code></pre>
  
  <p>How can I write simple JUnit test to check if this method works fine? Of course, in this case, I have entity <code>Book</code></p>