docs: def order_by(self, *args):
          """
          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.
  
  
          """
          if self._solr_locked:
              raise Exception("Query already executed, no changes can be made."
                              "%s %s" % (self._solr_query, self._solr_params)
                              )
  
          for arg in args:
              if arg.startswith('-'):
                  self._solr_params['sort'][arg[1:]] = 'desc'
              else:
                  self._solr_params['sort'][arg] = 'asc'