code: def one(self, default=None, as_dict=False, as_ordereddict=False):
          
  
          # Ensure that we don't have more than one row.
          try:
              self[1]
          except IndexError:
              return self.first(default=default, as_dict=as_dict, as_ordereddict=as_ordereddict)
          else:
              raise ValueError('RecordCollection contained more than one row. '
                               'Expects only one row when using '
                               'RecordCollection.one')
docs: Returns a single record for the RecordCollection, ensuring that it
          is the only record, or returns `default`. If `default` is an instance
          or subclass of Exception, then raise it instead of returning it.