presto-main/src/main/java/io/prestosql/server/security/JsonWebTokenAuthenticator.java/DynamicKeyLoader/apply
class DynamicKeyLoader:        @Override
        public Key apply(JwsHeader<?> header)
        {
            String keyId = getKeyId(header);
            SignatureAlgorithm algorithm = SignatureAlgorithm.forName(header.getAlgorithm());
            return keys.computeIfAbsent(keyId, this::loadKey).getKey(algorithm);
        }