Flushes the cache content.

        Usage::

            >>> cache = Cache()
            >>> cache.add_content(John="Doe", Luke="Skywalker")
            True
            >>> cache.flush_content()
            True
            >>> cache
            {}

        :return: Method success.
        :rtype: bool

def flush_content(self):
        """
        Flushes the cache content.

        Usage::

            >>> cache = Cache()
            >>> cache.add_content(John="Doe", Luke="Skywalker")
            True
            >>> cache.flush_content()
            True
            >>> cache
            {}

        :return: Method success.
        :rtype: bool
        """

        LOGGER.debug("> Flushing cache content.".format(self.__class__.__name__))

        self.clear()
        return True