title: How to override isEmpty method of JsonSerializer for specific class without overriding serialize method?
body: <p>I want to add custom behaviour for <strong>isEmpty</strong> method.</p>
  
  <p>When I extends from <code>JsonSerializer&lt;MySpecificClass&gt;</code></p>
  
  <p>I should override serialize method because it abstract.</p>
  
  <p>I want leave serialize method as is and override only isEmpty method.</p>