docs: def returns(self, obj):
          """
          Customizes the return values of the stub function. If conditions like withArgs or onCall
          were specified, then the return value will only be returned when the conditions are met.
  
          Args: obj (anything)
          Return: a SinonStub object (able to be chained)
          """
          self._copy._append_condition(self, lambda *args, **kwargs: obj)
          return self