code: def uniquify_by(self, column, chooser=None, aggregate='MAX'):
          
          self.group_by.append(column)
          if chooser:
              i = self.columns.index(chooser)
              self.columns[i] = '{0}({1})'.format(aggregate, self.columns[i])
docs: Group by `column` and run `aggregate` function on `chooser` column.