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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 find_value(self, key):
 """Find a value and return it"""

        values = self.values
        if key not in values:
            raise AttributeError("Config has no value for {}".format(key))

        val = values[key]
        if isinstance(val, Default):
            return val.val
        else:
            return val