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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 parse(cls, backend, ik, spk, spk_signature, otpks):
 """ Use this method when creating a bundle from data you retrieved directly from some PEP node. This method applies an additional decoding step to the public keys in the bundle. Pass the same structure as the constructor expects. """


        ik = backend.decodePublicKey(ik)[0]

        spk["key"] = backend.decodePublicKey(spk["key"])[0]

        otpks = list(map(lambda otpk: {
            "key" : backend.decodePublicKey(otpk["key"])[0],
            "id"  : otpk["id"]
        }, otpks))

        return cls(ik, spk, spk_signature, otpks)