code: def get_ordering_for_column(self, column, direction):
          
          if direction == 0:
              return ()
          if column in self.orderings:
              ordering = self.orderings[column]
          else:
              field = self.get_field(column)
              if field is None:
                  return ()
              ordering = column
          if not isinstance(ordering, (tuple, list)):
              ordering = [ordering]
          if direction == 1:
              return ordering
          return [lookup[1:] if lookup[0] == '-' else '-' + lookup
                  for lookup in ordering]
docs: Returns a tuple of lookups to order by for the given column
          and direction. Direction is an integer, either -1, 0 or 1.