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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 resolve(self):
 """ Resolve differences between the target and the source configuration """

        if self.source and self.target:
            for key in self.source.keys():
                if (key not in self.dont_carry_over_options
                        and not self.target.has(key)):
                    self.target.set(key, self.source.get(key))