sign(sender) wraps the envelope before signing, so the seal pipeline is wrap → addSignature → wrap → encryptToRecipient: the reference's seal, self.sign(sender).encrypt_to_recipient(recipient).
sign(sender)
wrap → addSignature → wrap → encryptToRecipient
seal
self.sign(sender).encrypt_to_recipient(recipient)
sign(sender)wraps the envelope before signing, so the seal pipeline iswrap → addSignature → wrap → encryptToRecipient: the reference'sseal,self.sign(sender).encrypt_to_recipient(recipient).