title: Add QStatusBar in a QVBoxLayout
body: <p>I need to add a status bar beneath a table in a <code>QVBoxLayout</code>. The problem is that I don't know why status bar is not shown. In the <code>QBoxLayout</code>, I have added a tableView, under the table I need to have the status bar. Here is part of my code:</p>
  
  <pre><code>  self.setGeometry(200,200,600,600)
    if self._model.productName()!='':
      self.setWindowTitle('TITLE')
    QVBoxLayout(self).addWidget(self.tv)
  
    # add staus bar
    statusBar = QStatusBar()
    statusLabel = QLabel("Here comes the status bar message!!")
    statusBar.addWidget(statusLabel)
    QVBoxLayout(self).addWidget(statusBar)
  </code></pre>