def set(self, style={}):
        """overrides style values at the current stack level"""
        _style = {}
        for attr in style:
            if attr in self.cmds and not style[attr] in self.cmds[attr]:
                print 'WARNING: ESC/POS PRINTING: ignoring invalid value: '+utfstr(style[attr])+' for style: '+utfstr(attr)
            else:
                self.stack[-1][attr] = self.enforce_type(attr, style[attr])