docs: def update(self, enabled=None):
          """
          Updates this item based on the interface.
          """
          if enabled is None:
              enabled = self.checkState(0) == QtCore.Qt.Checked
          elif not enabled or self._element.get('enabled', 'True') != 'True':
              self.setCheckState(0, QtCore.Qt.Unchecked)
          else:
              self.setCheckState(0, QtCore.Qt.Checked)
          
          if enabled:
              self.setForeground(0, QtGui.QBrush())
          else:
              self.setForeground(0, QtGui.QBrush(QtGui.QColor('lightGray')))
  
          for child in self.children():
              child.update(enabled)