code: func SigncryptArmor62Seal(plaintext []byte, ephemeralKeyCreator EphemeralKeyCreator, sender SigningSecretKey, receiverBoxKeys []BoxPublicKey, receiverSymmetricKeys []ReceiverSymmetricKey, brand string) (string, error) {
  	return signcryptArmor62Seal(plaintext, sender, receiverBoxKeys, receiverSymmetricKeys, ephemeralKeyCreator, defaultSigncryptRNG{}, brand)
  }
docs: // SigncryptArmor62Seal is the non-streaming version of NewSigncryptArmor62SealStream, which
  // inputs a plaintext (in bytes) and output a ciphertext (as a string).
  //
  // ephemeralKeyCreator should be the last argument; it's the 2nd one
  // to preserve the public API.