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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 data(self):
 """ Returns signed data if present in the message """

        # Check if signatire is detached
        if self.detached:
            return None
        bio = Membio()
        if not libcrypto.CMS_verify(self.ptr, None, None, None, bio.bio,
                                    Flags.NO_VERIFY):
            raise CMSError("extract data")
        return str(bio)