public static PGPPublicKey mergeSignatures(PGPPublicKey targetKey,PGPPublicKey sourceKey) throws PGPException {
  if (!Objects.deepEquals(targetKey.getFingerprint(),sourceKey.getFingerprint())) {
    throw new IllegalArgumentException("Signature merge can be done for different instances of the same public key only");
  }
  return copySignatures(targetKey,sourceKey);
}

public static PGPPublicKey mergeSignatures ( PGPPublicKey targetKey , PGPPublicKey sourceKey ) throws PGPException { if ( ! Objects . deepEquals ( targetKey . getFingerprint ( ) , sourceKey . getFingerprint ( ) ) ) { throw new IllegalArgumentException ( "Signature merge can be done for different instances of the same public key only" ) ; } return copySignatures ( targetKey , sourceKey ) ; }
returns a public key containing signatures of two keys .
