docs: def clear(self):
          """
          Clears out this toolbar from the system.
          """
          # preserve the collapse button
          super(XToolBar, self).clear()
          
          # clears out the toolbar
          if self.isCollapsable():
              self._collapseButton = QToolButton(self)
              self._collapseButton.setAutoRaise(True)
              self._collapseButton.setSizePolicy(QSizePolicy.Expanding,
                                                 QSizePolicy.Expanding)
              
              self.addWidget(self._collapseButton)
              self.refreshButton()
              
              # create connection
              self._collapseButton.clicked.connect(self.toggleCollapsed)
          
          elif self._collapseButton:
              self._collapseButton.setParent(None)
              self._collapseButton.deleteLater()
              self._collapseButton = None