Returns the list of labels that will be used to represent
        this axis' information.
        
        :return     [<str>, ..]

def labels(self):
        """
        Returns the list of labels that will be used to represent
        this axis' information.
        
        :return     [<str>, ..]
        """
        if self._labels is None:
            self._labels = map(self.labelFormat().format, self.values())
        return self._labels