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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 add_substitution(self, substitution):
 """Add a new Substitution to this Personalization. :type substitution: Substitution """

        if isinstance(substitution, dict):
            self._substitutions.append(substitution)
        else:
            self._substitutions.append(substitution.get())