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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_value(self, var_name, value):
 """Set the value of a given variable to a given value. Parameters var_name : str The name of the variable in the model whose value should be set. value : float The value the variable should be set to """

        if var_name in self.outside_name_map:
            var_name = self.outside_name_map[var_name]
            print('%s=%.5f' % (var_name, 1e9*value))
            if var_name == 'Precipitation':
                value = 1e9*value
        species_idx = self.species_name_map[var_name]
        self.state[species_idx] = value