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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 get_reaction_values(self, reaction_id):
 """Return stoichiometric values of reaction as a dictionary"""

        if reaction_id not in self._reaction_set:
            raise ValueError('Unknown reaction: {}'.format(repr(reaction_id)))
        return self._database.get_reaction_values(reaction_id)