<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def has_readable_server(self, read_preference=ReadPreference.PRIMARY):
 """Does this topology have any readable servers available matching the given read preference? :Parameters: - `read_preference`: an instance of a read preference from :mod:`~pymongo.read_preferences`. Defaults to :attr:`~pymongo.read_preferences.ReadPreference.PRIMARY`. .. note:: When connected directly to a single server this method always returns ``True``. .. versionadded:: 3.4 """

        common.validate_read_preference("read_preference", read_preference)
        return any(self.apply_selector(read_preference, None))