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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 set_active(self, ind):
 """ ind is a list of index numbers for the axes which are to be made active """

        DEBUG_MSG("set_active()", 1, self)
        self._ind = ind
        if ind != None:
            self._active = [ self._axes[i] for i in self._ind ]
        else:
            self._active = []
        # Now update button text wit active axes
        self._menu.updateButtonText(ind)