code: def set_main_style(widget):
      
      load_all_resources()
      with open(MAIN_STYLESHEET, 'r') as qss:
          sheet = qss.read()
      widget.setStyleSheet(sheet)
docs: Load the main.qss and apply it to the application
  
      :param widget: The widget to apply the stylesheet to.
                     Can also be a QApplication. ``setStylesheet`` is called on the widget.
      :type widget: :class:`QtGui.QWidget`
      :returns: None
      :rtype: None
      :raises: None