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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 shrink (self):
 """Shrink ca. 5% of entries."""

        trim = int(0.05*len(self))
        if trim:
            items = super(LFUCache, self).items()
            # sorting function for items
            keyfunc = lambda x: x[1][0]
            values = sorted(items, key=keyfunc)
            for item in values[0:trim]:
                del self[item[0]]