code: @Override
      public PGPPublicKeyRingCollection getAnnouncedPublicKeys() throws IOException, PGPException {
          PGPSecretKeyRing secretKeys = getSigningKeyRing();
          PGPPublicKeyRing publicKeys = getAnyPublicKeys().getPublicKeyRing(secretKeys.getPublicKey().getKeyID());
          publicKeys = BCUtil.removeUnassociatedKeysFromKeyRing(publicKeys, secretKeys.getPublicKey());
          return new PGPPublicKeyRingCollection(Collections.singleton(publicKeys));
      }
docs: Return a {@link PGPPublicKeyRingCollection} containing only the public keys belonging to our signing key ring.
  TODO: Add support for public keys of other devices of the owner.
  
  @return public keys
  
  @throws IOException IO is dangerous.
  @throws PGPException PGP is brittle.