Returns a table of Twitter user data, with "tweets" as rows/observations.

        .. note::

            drop_collections is not available for this method, since there are no meaningful collections to keep.

        :return: pandas.DataFrame

def tweets(self):
        """
        Returns a table of Twitter user data, with "tweets" as rows/observations.

        .. note::

            drop_collections is not available for this method, since there are no meaningful collections to keep.

        :return: pandas.DataFrame
        """

        # I've hard coded these. Seemed like a good idea at the time...
        # TODO: Fix this.
        all_columns = ['contributors_enabled', 'created_at', 'default_profile',
                       'default_profile_image', 'description', 'entities', 'favourites_count',
                       'follow_request_sent', 'followers_count', 'following', 'friends_count',
                       'geo_enabled', 'has_extended_profile', 'id_str',
                       'is_translation_enabled', 'is_translator', 'lang', 'listed_count',
                       'location', 'name', 'needs_phone_verification', 'notifications',
                       'profile_background_color', 'profile_background_image_url',
                       'profile_background_image_url_https', 'profile_background_tile',
                       'profile_banner_url', 'profile_image_url', 'profile_image_url_https',
                       'profile_link_color', 'profile_location',
                       'profile_sidebar_border_color', 'profile_sidebar_fill_color',
                       'profile_text_color', 'profile_use_background_image', 'protected',
                       'screen_name', 'statuses_count', 'suspended', 'time_zone',
                       'translator_type', 'url', 'utc_offset', 'verified', 'tweets/created',
                       'tweets/retweet', 'tweets/rt author', 'tweets/text']

        keep_columns = ['id_str', 'lang', 'location', 'name',
                        'protected', 'screen_name','time_zone',
                        'utc_offset', 'tweets/created', 'tweets/retweet',
                        'tweets/rt author', 'tweets/text']

        drop_columns = list(set(all_columns).difference(set(keep_columns)))

        base_df = self.expand_on('id', 'tweets', rename1='id', rename2='tweet_id', drop=drop_columns)

        return self._drop_collections(base_df)