Allows to add one or more sort on specific fields. Each sort can be reversed as well. The sort is defined on a per field level, with special field name for _score to sort by score.

def sorted(self, fsort):
        '''
        Allows to add one or more sort on specific fields. Each sort can be reversed as well. The sort is defined on a per field level, with special field name for _score to sort by score.
        '''
        if not self.params:
            self.params = dict()
        self.params['sort'] = fsort

        return self