title: What the correct way to create a stub using minitest?
body: <p>I'm having issues creating a stub for the tests I'm running using <code>minitest (4.7.0)</code>. I've tried the following from what I've researched from previous SO questions and it doesn't work:</p>
  
  <p><strong>test/model/book_test.rb</strong></p>
  
  <pre><code>Book.stub :title, "War and Peace" do
    book = Book.new
    book.title.must_equal "War and Peace"
  end
  </code></pre>
  
  <p><strong>error</strong><br></p>
  
  <pre><code>NameError: undefined method 'title' for `Book'
  </code></pre>
  
  <p><strong>app/models/book.rb</strong></p>
  
  <pre><code>class Book  
   #I tried adding the following according to the github readme but it doesn't work:
   #def title.fake_method
   #end
  end
  </code></pre>