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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 _realGetInstalledThemes(self, store):
 """ Collect themes from all offerings installed on this store. """

        l = []
        for offering in getInstalledOfferings(store).itervalues():
            l.extend(offering.themes)
        l.sort(key=lambda o: o.priority)
        l.reverse()
        return l