<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _return_assoc_tuple(self, objects):
 """ Create the property tuple for _imethod return of references, referencenames, associators, and associatornames methods. This is different than the get/enum imethod return tuples. It creates an OBJECTPATH for each object in the return list. _imethod call returns None when there are zero objects rather than a tuple with empty object path """

        if objects:
            result = [(u'OBJECTPATH', {}, obj) for obj in objects]
            return self._make_tuple(result)

        return None