title: PyQt5 Fixed Window Size
body: <p>I am trying to set my window / QDialog to not be resizable. </p>
  
  <p>I found the following example
      <code>self.setFixedSize(self.size())</code></p>
  
  <p>I'm not sure how to implement this. I can put it in the .py file generated from Qt Designer or explicitly using:</p>
  
  <pre><code>QtWidgets.QDialog().setFixedSize(self.size())
  </code></pre>
  
  <p>without errors but it's not working. Thanks.</p>