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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 is_compatible(self, model, version):
 """ Check if this flag is compatible with a YubiKey of version 'ver'. """

        if not model in self.models:
            return False
        if self.max_ykver:
            return (version >= self.min_ykver and
                    version <= self.max_ykver)
        else:
            return version >= self.min_ykver