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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def remove_cycle_mrkr(self):
 """Remove cycle marker."""

        window_start = self.parent.value('window_start')

        try:
            self.annot.remove_cycle_mrkr(window_start)

        except KeyError:
            msg = ('The start of the window does not correspond to any cycle '
                   'marker in sleep scoring file')
            self.parent.statusBar().showMessage(msg)
            lg.debug(msg)

        else:
            lg.debug('User removed cycle marker at' + str(window_start))
            #self.trace
            self.parent.overview.update(reset=False)
            self.parent.overview.display_annotations()