'Flushes one or more indices (clear memory)
If a bulk is full, it sends it.
(See :ref:`es-guide-reference-api-admin-indices-flush`)
:keyword indices: an index or a list of indices
:keyword refresh: set the refresh parameter'

def flush(self, indices=None, refresh=None):

    self.conn.force_bulk()
    path = self.conn._make_path(indices, '_flush')
    args = {}
    if (refresh is not None):
        args['refresh'] = refresh
    return self.conn._send_request('POST', path, params=args)
