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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 set_basic(self, realm='authentication required'):
 """Clear the auth info and enable basic auth."""

        dict.clear(self)
        dict.update(self, {'__auth_type__': 'basic', 'realm': realm})
        if self.on_update:
            self.on_update(self)