def mirror(self, axes='x', inplace=False):
        """
        Generates a symmetry of the Space respect global axes.
        
        :param axes: 'x', 'y', 'z', 'xy', 'xz', 'yz'...
        :type axes: str
        :param inplace: If True, the new ``pyny.Space`` is copied and 
            added to the current ``pyny.Space``. If False, it returns 
            the new ``pyny.Space``.
        :type inplace: bool        
        :returns: None, ``pyny.Space``
        """
        state = Polygon.verify
        Polygon.verify = False
        mirror = np.ones(3)
        if 'x' in axes:
            mirror *= np.array([-1, 1, 1])
        if 'y' in axes:
            mirror *= np.array([1, -1, 1])
        if 'z' in axes:
            mirror *= np.array([1, 1, -1])
        
        map_ = self.get_map()[1] * mirror
        space = self.map2pyny(map_)
        
        Polygon.verify = state
        if inplace:
            self.add_spaces(space)
            return None
        else:
            return space