Append label for ``mode`` and display ``value`` on it.

        |Args|

        * ``mode`` (**str**): mode of mode.
        * ``value`` (**object**): value of mode.

        |Returns|

        * **None**

        |Raises|

        * **QtmacsArgumentError** if at least one argument has an invalid type.

def qteAddMode(self, mode: str, value):
        """
        Append label for ``mode`` and display ``value`` on it.

        |Args|

        * ``mode`` (**str**): mode of mode.
        * ``value`` (**object**): value of mode.

        |Returns|

        * **None**

        |Raises|

        * **QtmacsArgumentError** if at least one argument has an invalid type.
        """
        # Add the label to the layout and the local mode list.
        label = self._qteGetLabelInstance()
        label.setText(value)
        self._qteModeList.append((mode, value, label))
        self._qteUpdateLabelWidths()