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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 getBytesForString(self, u):
 """ Returns the corresponding utf-8 encoded string for a given unicode object. If there is no string, one is encoded. @since: 0.6 """

        h = hash(u)
        s = self._unicodes.get(h, None)

        if s is not None:
            return s

        s = self._unicodes[h] = u.encode('utf-8')

        return s