def order_by(self, *args):
if self._solr_locked:<EOL><INDENT>raise Exception("<STR_LIT>"<EOL>"<STR_LIT>" % (self._solr_query, self._solr_params)<EOL>)<EOL><DEDENT>for arg in args:<EOL><INDENT>if arg.startswith('<STR_LIT:->'):<EOL><INDENT>self._solr_params['<STR_LIT>'][arg[<NUM_LIT:1>:]] = '<STR_LIT>'<EOL><DEDENT>else:<EOL><INDENT>self._solr_params['<STR_LIT>'][arg] = '<STR_LIT>'<EOL><DEDENT><DEDENT>
Applies query ordering.

New parameters are appended to current ones, overwriting existing ones.

Args:
    **args: Order by fields names.
    Defaults to ascending, prepend with hypen (-) for desecending ordering.