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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 class_for_type(self, object_type):
 """ Given an object_type return the class associated with it. """

        if object_type not in self.class_mapping:
            raise ZenpyException("Unknown object_type: " + str(object_type))
        else:
            return self.class_mapping[object_type]