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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def allow_relation(self, obj1, obj2, **hints):
 """ Relations between objects are allowed between nodeshot2 objects only """

        if obj1._meta.app_label != 'oldimporter' and obj2._meta.app_label != 'oldimporter':
            return True
        return None