presto-jdbc/src/main/java/io/prestosql/jdbc/PrestoDriverUri.java/PrestoDriverUri/mergeConnectionProperties
class PrestoDriverUri:    private static Properties mergeConnectionProperties(URI uri, Properties driverProperties)
            throws SQLException
    {
        Map<String, String> defaults = ConnectionProperties.getDefaults();
        Map<String, String> urlProperties = parseParameters(uri.getQuery());
        Map<String, String> suppliedProperties = Maps.fromProperties(driverProperties);

        for (String key : urlProperties.keySet()) {
            if (suppliedProperties.containsKey(key)) {
                throw new SQLException(format("Connection property '%s' is both in the URL and an argument", key));
            }
        }

        Properties result = new Properties();
        setProperties(result, defaults);
        setProperties(result, urlProperties);
        setProperties(result, suppliedProperties);
        return result;
    }