title: filepath of children
body: <p><code><pre>class a1 extends class b{}
  class a2 extends class b{}
  class a3 extends class b{}
  class a4 extends class b{}
  class a5 extends class b{}
  </pre></code></p>
  
  <p>I need $this->filePath in each a1 to a5 that point to location of it's file, but when I set $this->filePath = __FILE__ in parent, in children $this->filePath point to parent location</p>