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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 get_range(self):
 """ Return the possible types for this parameter's value. (I.e. return {name: <class>} for all classes that are concrete_descendents() of self.class_.) Only classes from modules that have been imported are added (see concrete_descendents()). """

        classes = concrete_descendents(self.class_)
        d=OrderedDict((name,class_) for name,class_ in classes.items())
        if self.allow_None:
            d['None']=None
        return d