execute a NON-cached, throttled einfo query

        einfo.fcgi?db=<database>

        Input: Entrez database (&db) or None (returns info on all Entrez databases)

        Output: XML containing database statistics

        Example: Find database statistics for Entrez Protein.

            QueryService.einfo({'db': 'protein'})

        Equivalent HTTP request:

            https://eutils.ncbi.nlm.nih.gov/entrez/eutils/einfo.fcgi?db=protein

        :param dict args: dict of query items (optional)
        :returns: content of reply
        :rtype: str
        :raises EutilsRequestError: when NCBI replies, but the request failed (e.g., bogus database name)

def einfo(self, args=None):
        """
        execute a NON-cached, throttled einfo query

        einfo.fcgi?db=<database>

        Input: Entrez database (&db) or None (returns info on all Entrez databases)

        Output: XML containing database statistics

        Example: Find database statistics for Entrez Protein.

            QueryService.einfo({'db': 'protein'})

        Equivalent HTTP request:

            https://eutils.ncbi.nlm.nih.gov/entrez/eutils/einfo.fcgi?db=protein

        :param dict args: dict of query items (optional)
        :returns: content of reply
        :rtype: str
        :raises EutilsRequestError: when NCBI replies, but the request failed (e.g., bogus database name)

        """
        if args is None:
            args = {}
        return self._query('/einfo.fcgi', args, skip_cache=True)