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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 getCachedOrUpdatedValue(self, key, channel=None):
 """ Gets the channel's value with the given key. If the key is not found in the cache, the value is queried from the host. If 'channel' is given, the respective channel's value is returned. """

        if channel:
            return self._hmchannels[channel].getCachedOrUpdatedValue(key)

        try:
            return self._VALUES[key]
        except KeyError:
            value = self._VALUES[key] = self.getValue(key)
            return value