Remove the highlighting from previously highlighted characters.

        The method access instance variables to determine which
        characters are currently highlighted and have to be converted
        to non-highlighted ones.

        |Args|

        * ``widgetObj`` (**QWidget**): the ``QTextEdit`` to use.

        |Returns|

        * **None**

        |Raises|

        * **None**

def qteRemoveHighlighting(self, widgetObj):
        """
        Remove the highlighting from previously highlighted characters.

        The method access instance variables to determine which
        characters are currently highlighted and have to be converted
        to non-highlighted ones.

        |Args|

        * ``widgetObj`` (**QWidget**): the ``QTextEdit`` to use.

        |Returns|

        * **None**

        |Raises|

        * **None**
        """

        # Retrieve the widget specific macro data.
        data = self.qteMacroData(widgetObj)
        if not data:
            return

        # If the data structure is empty then no previously
        # highlighted characters exist in this particular widget, so
        # do nothing.
        if not data.matchingPositions:
            return

        # Restore the original character formats, ie. undo the
        # highlighting changes.
        self.highlightCharacters(widgetObj, data.matchingPositions,
                                 QtCore.Qt.black, 50, data.oldCharFormats)

        # Clear the data structure to indicate that no further
        # highlighted characters exist in this particular widget.
        data.matchingPositions = None
        data.oldCharFormats = None
        self.qteSaveMacroData(data, widgetObj)