<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def base_concrete_modeladmin(self):
 """ The class inheriting directly from ContentModelAdmin. """

        candidates = [self.__class__]
        while candidates:
            candidate = candidates.pop()
            if ContentTypedAdmin in candidate.__bases__:
                return candidate
            candidates.extend(candidate.__bases__)

        raise Exception("Can't find base concrete ModelAdmin class.")