docs: public PGPPublicKeyRingCollection getTrustedAnnouncedKeys()
              throws IOException, PGPException {
          PGPPublicKeyRingCollection announced = getAnnouncedPublicKeys();
          PGPPublicKeyRingCollection trusted = getPublicKeysOfTrustState(announced, OpenPgpTrustStore.Trust.trusted);
          return trusted;
      }