code: def set_corner_widgets(self, corner_widgets):
          
          assert isinstance(corner_widgets, dict)
          assert all(key in (Qt.TopLeftCorner, Qt.TopRightCorner)
                     for key in corner_widgets)
          self.corner_widgets.update(corner_widgets)
          for corner, widgets in list(self.corner_widgets.items()):
              cwidget = QWidget()
              cwidget.hide()
              prev_widget = self.cornerWidget(corner)
              if prev_widget:
                  prev_widget.close()
              self.setCornerWidget(cwidget, corner)
              clayout = QHBoxLayout()
              clayout.setContentsMargins(0, 0, 0, 0)
              for widget in widgets:
                  if isinstance(widget, int):
                      clayout.addSpacing(widget)
                  else:
                      clayout.addWidget(widget)
              cwidget.setLayout(clayout)
              cwidget.show()
docs: Set tabs corner widgets
          corner_widgets: dictionary of (corner, widgets)
          corner: Qt.TopLeftCorner or Qt.TopRightCorner
          widgets: list of widgets (may contains integers to add spacings)