title: Correct way to make function available in multiple models
body: <p>In Laravel I have the following model:</p>
  
  <pre><code>class Product extends Model {}
  </code></pre>
  
  <p>which contains the function:</p>
  
  <pre><code>public function setThumbnailAttribute($value) {}
  </code></pre>
  
  <p>I have multiple models which should contain the same <code>setThumbnailAttribute()</code> function. What is the correct way to do this using Laravel or basic PHP functionality?</p>