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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 service to embed in DID document. """


        rv = {
            'id': self.id,
            'type': self.type,
            'priority': self.priority
        }
        if self.recip_keys:
            rv['routingKeys'] = [canon_ref(k.did, k.id, '#') for k in  self.recip_keys]
        if self.routing_keys:
            rv['routingKeys'] = [canon_ref(k.did, k.id, '#') for k in self.routing_keys]
        rv['serviceEndpoint'] = self.endpoint

        return rv