@Test
public void testString() throws IOException {

    final ByteArrayOutputStream baos = new ByteArrayOutputStream();
    final AJsonSerHelper ser = new AJsonSerHelper(baos);
    ser.writeStringLiteral("abcäöü\r\n\t \\\"{}[]");
    final String result = new String(baos.toByteArray(), "utf-8");
    assertEquals("\"abcäöü\\u000d\\u000a\\u0009 \\\\\\\"{}[]\"", result);
}