<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _set_tk_config(self, keys, value):
 """ Gets the config from the widget's tk object :param string/List keys: The tk config key or a list of tk keys. :param variable value: The value to set. If the value is `None`, the config value will be reset to its default. """


        # if a single key is passed, convert to list
        if isinstance(keys, str):
            keys = [keys]

        # loop through all the keys
        for key in keys:
            if key in self.tk.keys():
                if value is None:
                    # reset to default
                    self.tk[key] = self._tk_defaults[key]
                else:
                    self.tk[key] = value