Extend the True elements by n when setting the conditions
        based on a 'stopcond' condition.

        n is an integer >= 0.

        .. note::
           Updates the mask if not no_auto.

def set_stopextend(self, n):
        """Extend the True elements by n when setting the conditions
        based on a 'stopcond' condition.

        n is an integer >= 0.

        .. note::
           Updates the mask if not no_auto.
        """
        self.conconf.set_condition('stopextend', n)
        if not self.no_auto:
            self.make_mask()