def add_places(self, places, ret=False):
        """
        Add ``pyny.Places`` to the current space.
        
        :param places: Places to add.
        :type places: list of pyny.Place
        :param ret: If True, returns the whole updated Space. 
        :type ret: bool
        :returns: None, ``pyny.Space``
        
        .. warning:: This method acts inplace.
        """
        if type(places) != list: places = [places]        
        self.places += places
        if ret: return self