presto-client/src/main/java/io/prestosql/client/ClientTypeSignature.java/ClientTypeSignature/toString
class ClientTypeSignature:    @Override
    public String toString()
    {
        if (rawType.equals(ROW)) {
            return rowToString();
        }

        if (arguments.isEmpty()) {
            return rawType;
        }
        return rawType + arguments.stream()
                .map(ClientTypeSignatureParameter::toString)
                .collect(joining(",", "(", ")"));
    }