title: How does the expect().to.be.true work in Chai?
body: <pre><code>expect(true).to.be.true;
  </code></pre>
  
  <p>In this code, all the 'to', 'be', 'true' seems to be an attribute of the object response from 'expect(true)'.</p>
  
  <p>How can these attributes work so that they can raise an exception?</p>