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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 order_by(self, field, orientation='ASC'):
 """ Indica los campos y el criterio de ordenamiento """

        if isinstance(field, list):
            self.raw_order_by.append(field)
        else:
            self.raw_order_by.append([field, orientation])

        return self