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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 to_dict(self):
 """ Return dict representation of public key to embed in DID document. """


        return {
            'id': self.id,
            'type': str(self.type.ver_type),
            'controller': canon_ref(self.did, self.controller),
            **self.type.specification(self.value)
        }